The World's Largest Rewrite: Stupid Sprite Tricks, Monsters Ate My Pants, Uncle Boonmee Who Can Recall His Past Delves

The whole series is here, and the first post explaining what is going on is here.

A note on links: Since the beginning, these posts have included links to OSE monster entries. Necrotic Gnome appears to be overhauling their site as part of a 2026 streamlining of the OSE collection (would have been nice if old links had redirected to the new ones, but I'm not going to look a gift SRD in the mouth). If I have time I may go back and fix all these links, but until I do, you can go here and see the OSE monster list.

A further note on the monster list: During the late summer of 2026, while I was editing the final posts in this series, OSE significantly revised its lists of monsters. Great for OSE's continued development as a system, but this exercise will stick to the old, simple, B/X list from our beginning post; I'm not going to go back and attempt to determine the placement of creatures such as the Tree-Beast of Tarktuktulak.

 #113: Sprite. Quite similar to pixies, which we already covered as the “boring” ones. Sprites in OSE have a bit more to work with. Groups of five or more can curse someone, and they prank people instead of killing them, even after the offending party has attacked them. So the pixies are innocently trapped in the prison, while the sprites are intentionally making mischief. Tapping the Monster Overhaul again, we get a fly theme, and they’re drawing rude pictures. So they’re drawing graffiti all over the dungeon. They’re probably going to prank and ridicule PCs, but they could also be useful informants. Anyone willing to pull a suitably outrageous prank on a powerful monster could earn their friendship. Hm…

#17: Carcass Crawler. Why does OSE have an off-brand carrion crawler, but not equivalent rebranded monsters for the mindflayer and the beholder? Other retroclone and old-school/new-school systems are not shy about doing their own legally distinct versions of trademarked WotC monsters.

As an encounter, the OSE crawler is either trivial or a TPK. It doesn’t actually do any damage, and can only eat someone if “left in peace.” But it can attack eight times per round, and paralyzes people for 2d4 turns (on average, 50 minutes). PCs kiting it and peppering it with arrows can deal with it easily. A group surprised by it (or foolishly entering melee by choice) is asking for carcassification.

The Overhaul redirects to the monstrous vermin entry, which includes a carrion caterpillar that hits all the same beats. Lets treat the caterpillar aspect as literal and assume that this is the larval form of another monster. I already made a monstrous caterpillar, so I can just steal from myself. Adding the paralysis is nice. Imagine a caterpillar that paralyzes your entire party, eats your clothes off your body while you lie there helplessly, and then leaves you behind, naked but uninjured. TPK (total pants kill).

#2: Ape, White. The most confusing part of the OSE entry is the phrase “gorilla-like apes.” Gorillas… are apes? Anyway, they’re herbivorous, and enemies of our cavemen. Neanderthals hate this one weird ape.

Rolling on the Overhaul table, we get “retain hazy memories of their past lives as villagers, and sometimes watch and protect their descendants.” Is this an Uncle Boonmee situation? It certainly spices up an otherwise generic ape encounter. Perhaps the apes are the descendants of a village that was displaced for the construction of the prison. They would be a sympathetic faction, but highly mysterious, spiritual, and decidedly non-material. The neanderthals hate them due to a (probably misplaced) trust in the prison builders, who displaced the white apes when the complex was built. 

#121: Treant. With the carcass crawler I mentioned the monsters that are legally distinct adaptations of WotC monsters; it is worth remembering that D&D from its beginning has likewise had monsters who were in turn borrowed from elsewhere.

The treant is a straightforward protector of nature, and the relatively recent redirection of the river into the dungeon provides a pretty easy basis for them to be agitated. These treants probably dwell among the dryads we previously learned about, but are further removed from the prison builders. WIth their very slow sense of the progression of human-scale events, they may only be dimly aware of the prison at all.

#73: Medium. If you’re wondering why OSE has no entries for “wizard” or “mage” but includes a “medium” entry, it is because that is the title for a novice magic-user. This was actually true of several previous entries, like the acolyte.

The Overhaul includes a lavish five pages for wizards. So we have a trio of junior wizards – Shorth, Zephiros, and Claar – wandering around in this dungeon. Why are they here? Their notable spells are (respectively) Silence, Vertigo, and Glittergust. Shorth has a headless, hairless lemur as a familiar. Zephiors has a wand of knock/lock (quite handy in a prison). Claar is a teaching assistant at Blackspine, their wizarding school, so they are probably boss the two undergrads around. Their area of study is hallucinations! For “why is this wizard in the dungeon” we get “retracing the steps of their mentor,” which fits. Their mentor is (or is rumored to be) a prisoner here. 

 

#88: Orc. I have hundreds of words in my blog post drafts on orcs, racism, and associated RPG discourse. When I first read the Overhaul and looked up the orc entry, I learned that Skerples had covered the core of what I wanted to say better in a section on the orc page titled “The Problem of Evil,” essentially saying that orcs can be inherently evil, or they can be people like other creatures, but these two categories can’t be mixed. I believe that modern D&D keeps stepping on this rake because there is no coherent sense of this distinction.

For purposes of our current use-case, the orcs are harbingers of an invasion. Smoke on the horizon has signaled their approach. They can taste blood to learn secrets. Their prize tools are siege engines. They (apparently) seek to destroy the local religion.

So the orcs are here to undo the work of the celestial prison builders. Only a few patrols are present at the start of the scenario, but more appear, eventually displacing the external factions and using their siegeworks to dig into the prison. This provides a clock on a campaign set in the prison. They are not monsters that can be realistically beaten, but a force of nature that will eventually destroy the prison.

The Overhaul’s framing of orcs is rooted in rumors and suspicion, so there’s a strong chance that their motivation is somewhat different than what's described above. They may even prove to be a surprisingly pragmatic faction to deal with; more so than many of the prisoners and wardens, anyway.

#67: Living Statue. I think the classic animated statue has lost ground over D&D’s edition to the golems, with which it shares a lot in common. We can use the lawful crystal statue as a prison guardian. Their programmatic behavior means they serve faithfully, but they are inflexible and predictable, so the inmates are gradually isolating and destroying them. 

#48: Golem. Convenient to do these two back to back. I was surprised to see how much OSE’s golem entry differs from the the standard lineup that is pretty familiar in modern D&D: flesh (Frankensteinned), clay (closest to the original idea of the golem), stone (much more like OSE’s living statue), and iron (magical robot). OSE instead includes amber (animal-shaped tracker), bone (four-armed, non-undead), bronze (giant-sized, heated by fire within) and wood (small and simple).

Amber makes the most sense for our prison, but we already have an escaped-prisoner-tracking monster, so we’ll pick the bronze golem because it is the weirdest.

#89: Owl Bear. The D&D classic. For all of its brand recognition, it is mechanically interchangeable with a non-owl bear, a problem that continues up through modern D&D, where none of its history in the game makes it an interesting monster. Others have blogged about what a missed opportunity owlbears are, and how they could be more interesting.

Our Overhaul-informed leaves “dry log-sized pellets full of bones” and its mood of madness is “manic digging.” We already have burrowing monsters well-represented, but we could place the owlbear in the treant/dryad forest on top of the prison, and their dig sites could be dangerous but useful points of access to the upper parts of the prison. 

#112: Spider, Giant. Another classic. OSE has black widow (deadly poison), crab (camouflage), and tarantella (uncontrollable dancing). Choosing randomly, we get the last one. The Overhaul has armor as “if illuminated, as leather. In darkness, as plate+shield.” I love details like this that demonstrate how the Overhaul is willing to break from old-school orthodoxy when there’s a more interesting option. We’ll add extensive web spinning as a feature.

We’re in the home stretch. Just one more post after this, and we will be done with the entire OSE bestiary.

The World's Largest Rewrite: Octo-Cultists, Bug Ecology, Tortoise Tsar

Previous posts in this series are here if you want to try to understand what is going on here. On to the monsters.

#3: Bandit. Whereas OSE brigands are fighter-coded ruffians, the bandits are the thief-derived scoundrels. Going back to the Overhaul mercenary entry, we learn that their mission is to bulk up their numbers. So they’re here at the prison to recruit anyone (or anything) who is close to escaping, particularly if their help indebts the creature to them. In contrast to the loud and obvious brigand group, these bandits are keeping a low profile. 

The OSE entry notes they can have a leader of 2nd level or higher (any human class). Rolling randomly, we get magic-user. Using the Overhaul’s adventurer table we get “Smith M. Ledgermain,” which is sounds like a wizard forced to make up a fake name on the spot. He has a fancy feathered hat, is a spy, and has a hypnotic silver hand mirror. OK, so the bandits are here to recruit, but Ledgermain is also after a person of interest within the prison; probably someone he wants to kill. His bandit gang doesn’t know about this secret objective.

#124: Troll. The Overhaul entry gives us some good material to add around the classic vanilla OSE block. Apparently people call these trolls “night howlers.” While I don’t have any issue with players metagaming a troll encounter (because metagaming is good gaming), there’s an extra challenge if the DM never says the word “troll.” It requires the players to make the connection in order to gain the advantage. These troll pa-troll-ees (maybe? idk) specialize in “tragic ransoms.” They’re rubberized, so they can squeeze under some of the prison doors. Probably some kind of acid runoff from the black dragon is helping to keep them imprisoned. And of course these trolls are the source of our thouls.

#68: Lizard, Giant. Picking randomly we get the horned chameleon, who has a sticky tongue-grab attack, camouflage, and a knock-down tail attack. That’s plenty of action for a brute like this. We’ll treat these as steeds and guardians for our trepan lizards, who clearly need some muscle to support their brainy rule.

#1: Acolyte. There are seven of them, so they get a third-level leader. The Overhaul sends us to the cultist entry, where we learn that they lair in an ancient amphitheater, and their dark purpose is the manipulation of political events. Maybe their leader is Smith M. Ledgermain’s target? 

These cultists want to complete a ritual to summon an obedient avatar of their god, and the ritual requires crystals, bone, and ash, so they’re trying to collect those items within the dungeon. Apparently they follow Garnsolex the Kraken! Perhaps Garnsolex is one of those giant intelligent octopi we heard about earlier. Again using the Overhaul’s adventurer table to flesh out the acolyte's leader, we learn they are Ren Cullowsong, who has an octoparrot advisor. Perfect.

#129: Warp Beast. This is OSE’s non-trademark-infringing displacer beast. As previously mentioned, they hate -- and are hated in turn -- by blink dogs. The Overhaul, in yet another taxonomic choice I appreciate and agree with, groups both displacer beasts and blink dogs under the category of “shivered beast,” a catch-all for creatures that can violate Euclidian reality in some way. 

The entry includes a “displaced cat” to meet the demand for vanilla displacer beasts, but I’m more interested in one of the novel types from the shivered beast variant table. Choosing randomly, I get the underdog, a cunning lizard-hound that can appear or disappear under any unobserved space. It experiences gravity in an inverted way, and has a double climb speed. I like this as an imprisoned creature that is trying to escape, but is also the principal foe of the blink dogs.

#98: Robber Fly. Three-foot long flies that hunt killer bees. Once again, the implied ecosystem is interesting. They hunt killer bees and are immune to their venom. They are in turn preyed on by giant tiger beetles. Our intelligent factions are going to want to exploit robber flies too, because they can kill bees, which control the valuable honey. Not every monster needs to be part of an ecological chain like this, but done in moderation, it really improves what could be “just another giant bug” in a vacuum. 

#66: Leech, Giant. Speaking of giant bugs... here's the leeches. While OSE giant leeches have six times as many hit dice as stirges, they only drain at twice the rate. The Overhaul gives us a few entries to borrow from, including marine worm. The lamprey variant heals when it bites. That works for me.

#33: Dryad. Dryads must stay near their trees, so they're helpful to the celestials as "guardians" who won't just leave. Perhaps the prison builders enticed them to move here by promising to protect their trees. They’ve charmed both intruders and prison escapees and are becoming increasingly paranoid as the local situation gets worse. One or more of the dryads is injured and that’s why the unicorn is here.

#43: Ghoul. I considered creating a ghoul that is closer to the ghūl origins of the term (a shapeshifting “demon,” something like a djinni), but I think it would require a deeper study of the mythology to do it justice. For now, we will stick with the familiar fantasy genre representation of the ghoul as a corpse-eating, paralysis-inducing undead creature. Monster Overhaul, take the wheel.

The ghouls’ corpse acquisition scheme is a massive tunnel collapse. Perhaps they’re digging under the prison, hoping to undermine sections of the prison and feast upon the prisoners. No one will miss those terrible prisoners, right? The ghouls will even parlay with the PCs, seeking information about the greatest concentrations of sapient creatures (the Overhaul notes they specifically eat the flesh of intelligent creatures). This would be an interesting moral dilemma for the PCs; would they be willing to ally with the ghouls, in the interest of taking out a “worse” faction of non-undead creatures?

#31: Dragon Turtle. The dragon turtle fills the same well-populated sea monster niche as the sea serpent and giant tentacled things, although it has a bit more flair (steam breath, mistaken for an island). But we planned for this. 

Most of the Monster Overhaul covers the classic monsters one would expect in a fantasy RPG; goblins, dragons, zombies, normal humans. But I appreciate that the book also found room for unique creations of the blogging world, and the dragon turtle entry gives us an excuse to use one of them: the tortoise tsar.

This is a coal-eating, serf-oppressing turtle who eats coal. It is easy to imagine him ending up in prison. Over an IRL year ago, we learned that our fire elemental was summoned by the tsar, so he currently has some power within the prison. He’s currently scheming to get (1. more coal (2. more peasants and (3. his freedom. Tsar Yuri VIII has 11 peasants, listless and unmotivated, probably inmates he has recruited. He is noisily venting excess steam pressure and demanding tolls for passage. He probably controls a chokepoint in the dungeon, where he can use the steam to heat a metal passage or bridge to a dangerously hot temperature for anyone who refuses to pay his tolls. 

World's Largest Rewrite: Invisible Fire, Cube that Gets You High, IRL Bears

#19: Cave Locust. This is another of old-school D&D’s weird bugs, and another example of a superficially ordinary monster that has a lot going on. Cave locusts have five special features: stone camouflage, a random encounter-inducing shriek, a jump that can turn into an accidental attack, debilitating spit, and poison immunity. This makes it a surprisingly dynamic creature, where a lot of the outputs of encountering it are distinct from the conventional combat encounter.

They have poison immunity because they eat fungus, so we can put them in the vicinity of our previously established fungal creatures. They might be natural predators of the Mother Fungus, and thus implicit rivals of the gecko kobolds and other creatures who seek to exploit or symbiotically ally with the Mother Fungus. 

#52: Griffon. Like the hippogriff and the pegasus, the griffon is a member of the amply populated “flying animal mashup” category. Their urge to attack horses is their main distinguishing feature. 

…It doesn’t say they only attack mundane, land-bound horses, so perhaps they are predators to the hippogriffs and pegasi as well. At 7 HD, they are much bigger than either of those creature types, so they’re plausible as apex predators. Maybe shared fear of the griffon is the only thing keeping those rivals from attempting to drive the other out of the area. 

The Overhaul gives us a nice body variation table, similar to what we used for the chimera. We get lizard body (armor as plate) and peacock wings (half-speed flight). The peacock wings make it a slow and ungainly flyer, so it has to rely on ambush tactics to catch its swifter prey. Imagine an armored peacock the size of a garbage truck screaming in out of nowhere to try to eat you. I would be terrified too, and I’m not even a horse.

#120: Trader. Do you like duplicative stat blocks for barely distinguishable groups of humans? Because the OSE bestiary has duplicative stat blocks for barely distinguishable groups of humans. Our traders are only thinly sketched here, but appear to be lower on the tech tree than the merchants we met before (they trade in "carved wooden items, furs, spices").  

But they do have mules, which are canonically important to our dungeon! So I’m giving these guys a pass. We’ll put them inside the dungeon, to add some contrast with the merchants on the outside; they might have some useful supplies to offer adventurers. 

#20: Centaur. Uhh… how far do we want to take this griffons-eat-horses thing? I can’t think of any reason why the griffon would turn its nose up at a creature that is mostly horse… although with bows, the centaurs are at least better equipped to drive the griffon off. The Overhaul plays up the centaurs’ wild, rebellious side (“we bribed them to attack our enemies, but they spent our money on wine”). They’re prisoners trying to escape, but the griffon’s presence is making it hard for them to make a clean break for it.

#54: Harpy. Another classic monster, and the stat block is what you expect, although they have magic resistance with a +2 save, a feature they seem to have lost through the editions (the 2014 MM omits it). The Overhaul is similar, but does note that they are “divine servants of vengeance.” This harkens back to their origin in Greek myth, where they were usually acting to enact divine punishment, not just to serving as generic monsters. Like the wights and gargoyles, this is another opportunity to turn a conventionally evil monster, which would make sense as a prisoner, into part of the warden staff for the prison. Absent direct oversight from the prison builders, the harpies are experimenting with how shitty they can be without attracting celestial punishment. 

#56: Hellhound. OSE statblocks alternate between “yeah, what I expected” and “hold on, there’s some unexpected details here.” The hellhound is in the later category. They are “cunning, and very intelligent” but presumably not sapient, as other creatures keep them as pets. They have a variable HD range for some reason; it gives them more HP and more accurate attacks, but doesn’t change damage or anything else, so I’m not sure what purpose that serves. They can detect invisible things quite well, presumably reflecting their canine sense of smell and hearing, or their ability in myth (e.g., Japanese) to see through tricks.

The Overhaul variants are interesting. I rolled “Glass Hound. Invisible. Fire is also invisible.” So they’re trapped in the prison, they’ve broken containment, and they have started setting fires that burn like normal, but are invisible. Fire that you can smell and inhale, but not see, is a terrifying idea. How do you know you have actually put it out? This is not just a monster encounter, but an entire dungeon hazard for the PCs. Excellent. 

The invisible fire is such a huge problem that it explains why there's a river flowing through this prison. It wasn't an accident; it was deliberately diverted here to douse the invisible fires. 

#42: Gelatinous Cube. Deservedly one of the most famous and celebrated D&D monsters. This stat block is as expected. Like the basilisk, we could imagine the cube as a contained threat that was let loose in an attempt to stop other monsters from escaping. Like the blink dog, it can easily bypass bars and portcullises. It can devour other would-be escapees while making no effort of its own to escape. 

The Overhaul gives them a “wet wrinkly steak” texture and “gets you really high if you lick it.” So weaker dungeon denizens are being paralyzed and then eaten/and or intoxicated by the cube. Some factions have even captured smaller ones to intentionally take advantage of the intoxicating effect. I was gonna escape from prison, until I got high.

#71: Manticore. Like the griffon and so many others before it, this is another airborne mythological combo meal. The manticore’s ability to snipe from long range sets it apart from those other creatures, but it also has a finite amount of ammunition, so it needs to choose its targets carefully. The Overhaul adds some good lore, including that manticores propagating as evil dreams when they die, which would give the prison builders a good reason for capturing them, rather than killing them outright. This manticore is prowling an area of halls with doors too small for it to exit, using crudely made arrow slits to snipe and poison passerby. It cares more for these pointless acts of cruelty than it does for actions that might bring about its own freedom.

#7: Bear. Just use bears! You can do the entire WLD gimmick in no time at all. Just use bears! Who will notice? I would notice. I would know. I would be disappointed with you. I would be disappointed in myself. I’m too deep into this exercise to JUB my way out of it now.

Anyway, OSE includes four types of bears, and they map to their real-world counterparts pretty well in terms of size and combat danger. No sun bear stats, sadly.

One feature of the Overhaul that I enjoy is how it treats mundane animals. The 5E.2014 MM packs all the normal beasts into short bits at the back of the book, and I get it; you don’t need a lore block explaining what a deer is. But if they’re worth so little attention… why include them at all? The Overhaul, in contrast, is first and foremost a book for inspiring interesting encounters, rather than a book for referencing stats, and it has three tables of evocative bear variations. You could probably run several dozen bear encounters using the Overhaul with getting bored. I think you would be lucky to get one good bear encounter out of the 2014 manual.

To come full circle and return to our very first post in this series, our bears are here to GET THAT SWEET KILLER BEE HONEY. They’re probably immune or at least highly resistant to the stings. They’re “belligerent, secretive.” They’ve created a den within the prison that includes a “mummified carcass of an enormous bear.” They’re great! Just use bears!

#49: Gorgon. This is the Gygaxian gorgon, the metal bull that breathes petrifying gas. If you're really cool and smart like me, you know that this type of "gorgon" is actually a petroblepas. If we want to quadruple down on the stone theme, these creatures would be released for serious riot control situations, petrifying entire crowds of prisoners.

World's Largest Rewrite: Mickity Thumpduck and His Gang of Halflings are Horrible and They Aren't Even Prisoners Here

#61: Hydra. The hydra absolutely makes sense as a prisoner. It is interesting that the OSE hydra lacks the ability to regrow severed heads, which is core to modern D&D’s hydra. Rolling on the variant table in the Overhaul gets “centipede hydra.” Ew. But it immediately made me think of the cellipedes we introduced earlier. The cellipede hydra is the broodmother of all cellipedes, and each time a head is severed, a new one will grow, sprouting a brand-new key, which fits into a lock somewhere in the prison. The cellipede hydra becomes a sort of dynamic solution to barriers that the PCs can "harvest" keys from, but may not want to kill, to avoid missing out on future keys. 

#53: Halfling. Like our recent hits on dwarves and elves, halflings have basic OSE entries and no dedicated Overhaul entry. As with those previous cases, we can use the Overhaul’s adventurer section to get a feel for the local halflings. 

• Vice: Envy
• Goal: Drugs and retirement
• Why are they here: Utterly lost
• Subtype: Brawling
• Leader: Mickity Thumpduck; small eyes, leather cap; profession: justice; hidden miniature crossbow 
• From: Gamwich village, in the Stenrind region

I’ve praised the Overhaul a lot during this series, but I can’t stress enough how well-calibrated the tables are to produce gameable output. I could run Mickity Thumpduck and his idiot gang of corrupt rent-a-cops right now, no further prep needed. They heard about the dwarven treasure, showed up hoping to get a cut, and are now lost inside the prison.

#57: Herd Animal. Stampede is the interesting mechanical hook here. The Overhaul (understandably) does not not have entries for mundane moose and oxen, but it does have one for telluric goats. These are mineral-eating goats, so pose a bit of a rust monster-esque challenge for adventurers. Rolling on the tables in the entry, we get bite effect of “target’s head and body must face north” and a reason to fight them as “whenever telluric goats appear, landslides and earthquakes are sure to follow.” This suggests a possible reason for the insecurity of this previous secure underground prison. The goats began (or exacerbated) the decline of the prison, and now roam its halls, seeking delicious ore. 

#75: Merchant. Yeah, this is a separate entry from Normal Humans. The stat block itself is not important. The entry instead sketches out the size and composition of a merchant caravan, so we’ll follow the same logic and place these merchants outside the dungeon. They’re probably keeping their distance from the brigands, hoping to buy weird stuff that adventurers extract from the prison.

These caravans are big. I rolled 1d20 for number appearing and got 10 merchants. That means we have: 

• 10 mounts (one per merchant, implicitly?)
• 20 wagons (2 per merchant) with corresponding beasts of burden
• 40 L1 fighter guards (4 per merchant)
• 2 L2-3 fighter lieutenants (1 per 5 merchants)
• 1 5L fighter captain 
• 2 extra animals 

These guys are a serious force! For exterior factions, the brigands might be stronger, if there are enough of them to form a fortified camp and score a genuinely high-level leader (we didn’t nail down William Osprey’s level in the brigand entry). But even if the brigands are stronger, the merchants could put up enough of a fight to make them think twice about throwing down. So it is an uneasy detente outside the dungeon.

#114: Squid, Giant. As we foreshadowed in the giant octopus entry, OSE delivers too much tentacle-based trauma for one game to sustain. These cephalopods are broadly similar, with the giant squid differentiated the most by some boat-attack-focused abilities. As we did with giant octopus, we’ll again use the Overhaul’s kraken table for inspiration, and we get “vampiric.” This is a bit of a play on the real-life vampire squid, or Vampyroteuthis infernalis (vampire squid from hell) if you’re nasty. Wikipedia articles are an excellent source of monster content, and there’s no reason we can’t raid this one. Look at the spikes on that hood. Imagine this guy dropping on an adventurer’s head and draining their blood, while using strobing bioluminescent light to confuse and stun would-be rescuers. We can even be really literal and associate these guys with the vampire we already placed in the dungeon.

#110: Snake. Speak of the (vampire) devil, the next randomly chosen entry is for the snake. We already decided we wanted a giant albino snake to keep the vampire company, which brings Lair of the White Worm to mind. Snakes are nasty in OSE. We can size up the giant constrictor, and maybe give it a vampiric bite as well, depending on how we want to embellish the relationship between the vampire and the snake.

#136: Wyvern. From snakes to their heraldic descendants, wyverns. Like the snake, the wyvern has save-or-die poison. The Overhaul, interestingly, doesn’t treat the poison sting as a default feature. Rolling on the variant table, we get “Gulper: Neck sack, wattle, one nostril.” Imprisoned for its ravenously hungry behavior. 

#90: Pegasus. This far into this series, we have a lot less blue sky design, a lot more filling in spaces between already established monsters and factions. Pegasi are potential flying mounts for the jailers; the fighter jets to the bomber that is the roc we found earlier. They serve lawful characters. Perhaps the pegasi are no longer willing to aid the dwarves, sensing that some of them are compromised? 

#87: Ogre. They hate neanderthals. Otherwise, they’re bog-standard ogres. But the Overhaul can give us a tailored ogre.

• Name: Durl
• Feature: Thick forehead ridge
• Weapon: Hook and chain
• Crime: Despoiled sanctified ground
• Type: Fumeguts, leaks black fumes, twice per day, opaque fog, 30’ radius, 10 rounds

Locked up for farting in church. Sometimes these entries write themselves.

#102: Salamander. Ya got your hot lizards and your cold lizards. They are mostly similar, although flame salamanders are neutral, and frost types are chaotic. We'll choose the frost type as more fitting prisoners. The Overhaul directs to elemental spirit (where our gnome came from) and suggests barbegazi, which is more evocative than "salamander." These guys are "despised yet treasured local rivals" who look like "old, dark-eyed, serious men and women." That fits with a sort of frost witch folklore.

World's Largest Rewrite: Noble Neanderthals, Grimy Goblins, Execrable Elves

#80: Neanderthal (Caveman). Here we find more of the lost world vibe that is pretty strong in early D&D, but mostly gone from the modern game. The neanderthals are a bit more interesting than some of the other bestiary entries that can be boiled down to “Normal Human with slightly different equipment, group composition, and treasure.”

• Friendly with dwarves and gnomes. Turn that mancave into a demihumancave. 
• Lawful. Thog part of community. Thog honor social contract.
• Two 6HD leaders (one male, one female) live in the neanderthal lair. They are 10’ tall and of "a related but distinct race." I presume this comes from pulp fiction like Robert E. Howard’s stories and Shaver Mystery stuff; tales of speculative anthropology, crypto-history, devolution, and civilizational decline, suggesting that primitive humans might live under the sway of an older and more powerful species.
• Attack ogres on sight. Hate goblins and kobolds. They learned it from watching the dwarves?
• Sometimes keep white apes as pets. Who saved who?

Within our prison dungeon milieu, the neanderthals obviously make sense as members of the lost world “section” of the prison. But their alliance with dwarves and gnomes gives us another hook to work with. Let’s say that as the dwarves and their gnomish allies began to lose control of the prison, they thawed out the neanderthals and deputized them as prison security guards. The neanderthals and the dwarves are now separated by dangerous parts of the dungeon, with the dwarves toward the "south" and the neanderthals in the "north," where the lost world stuff is. 

#108: Shrieker. Of course prison builders in a D&D world would use shriekers as “alarms” to detect escapees. It is interesting that OSE shriekers can move, but very slowly. Shriekers in 5E are stationary (lazy). We can presume the shriekers have drifted somewhat from their original “stations.”

The Overhaul doesn’t have a shrieker entry, but we can revert back to the richly populated myconid entry we used for the Mother Fungus. On the hallucinogenic mushroom effects table, we get “Walls move and churn. Navigation difficult.” It would make sense that in addition to screaming, the shriekers would emit spores that would befuddle would-be escapees. This can also help explain why some prisoners haven’t yet escaped the prison; they're watching the walls melt.

#47: Goblin. The one detail from OSE that surprised me is that the king and bodyguards don’t suffer the sunlight penalty that affects ordinary goblins. Otherwise, these are your bog-standard gobbos. The Overhaul gives us five (!) pages on goblins, making them one of the most richly detailed monsters in the entire book. The Overhaul takes some liberties with the stat block, giving them 0 (!) HD (2 HP) and a morale of 4 (!), presumably to differentiate them more from other humanoid-style creatures that 1st-level PCs might encounter. Rolling on a few of the tables gives us some details:

• Special ability: Gravelmouth. Can digest anything.
• What are they doing: Malicious destruction.
• Leader: Bluck-ing Ding Tark. Necklace of teeth.
• Elite weapon: Boiling oil cauldron.
• Superweapon: Doomwand.
• Mounts: Larval worm. Hmm… maybe they’ve tamed some Caecilia?
• Loot: Turnips.
• Bullying target: Kobolds.
• Where goblins come from: “If you use a turnip as a ‘marital aid’ and plant it in a dunghill it grows into a Goblin." Skerples, why…
• Fear and response: Music; paralyzed
• Leadership method: Elective democracy

An embarrassment of riches. Democracy makes them our most commendable prisoners, although I don't like what they have been doing with it. Never eating a turnip again.

#77: Minotaur. The OSE minotaur is pretty basic. Dwells in mazes, charges like a bull. The Overhaul can beef it up (I’m sorry). 

• Why must this minotaur die? Technically the heir to the dying ruler’s throne. 
• Name: Harnthgar
• Feature: One blind eye
• Weapon: The Big Club

So our minotaur is a VIP (very important prisoner) who was put here because he is the heir to a powerful kingdom. Too important to kill, to dangerous/embarrassing to keep at court. One of god's own prototypes. Now there's some kind of succession crisis and the kingdom needs him, but there’s no easy way to retrieve him, due to the prison’s decline. Perhaps one or more of the organized factions on the outside, trying to get in, are seeking the minotaur?

#38: Elf. Elves don’t have a dedicated Overhaul entry, but we can once again use the Adventurer section to develop ideas. The tables there are intended for rival NPC adventuring parties, but mostly work just as well for a faction. These elves have…

• Vice: Distressing greed
• Goal: Bloodshed
• Why are they here: Found a map
• Subtype: High elves
• Leader: Vaeleth Duskstrider; unwrinkled, charming face; soldier; lifedrinking longsword
• From: Kethampton 

Oh, wonderful, I already hate these guys. Bloodthirsty, greedy elves in search of treasure. They are probably very well-mannered and good at putting up appearances, but are really just sadistically cruel shitheads.

#130: Water Termite. Ah, yes, the classic D&D monsters. Goblin, minotaur, elf… water termite. Again I am charmed by some of the OSE oddities that don’t appear in modern editions.

Like the beetles and rats, the mechanics of the water termite imply An Entire Situation. They are pests that consume wood, including the undersides of ships and boats, with a built-in chance of someone noticing their presence. They might have been drawn to the dungeon as the sea seeped into the lower levels, coming into contact with wood... delicious wood. They are probably also living inside the sperm whale’s stomach, feeding on the crashed ships therein. 

#76: Merman. Nothing surprising here. Let's go to the Overhaul.

• Leader: Tenchal 
• Feature: Sensory barbel-whiskers
• Lower half: Eel
• Trades/treasures: Untraceable poison
• Want: Return of a kidnapped merfolk

Once again the Overhaul’s random tables provide a connection that would not have otherwise occurred  to us. The merfolk are willing to trade an “untraceable poison,” probably derived from some deep-sea creature. Sounds like just the sort of thing our dwarven leader would have used, right? They’ve traded that poison for the freedom of a merfolk leader (Tenchal) trapped in the prison. The dwarves have to return this prisoner now, but that process is probably complicated by the distressed state of the prison. The merfolk are getting impatient…

#28: Djinni (Lesser). Like the sea serpent before it, we have a lesser creature with no greater equivalent. Maybe this is some inherited B/X design, where the “greater” creature is assumed to be something lower-powered PCs would never encounter.

Regardless, amid other, flashier powers, the djinni has two powers that are particularly interesting to our prison builders. They can use each of these three times per day.

• Illusion: Visual and audial. No concentration required. Remains until touched or dispelled.
• Conjure soft goods / wooden objects: Up to 1,000 coins weight. Permanent.

So a djinni is summoned and bound to serve the wardens. They have it spend its daily uses conjuring wooden objects – all the non-stone components of the dungeon, like the doors. This compliments the cockatrice/basilisk/medusa/gorgon system of stoneworking. The djinni uses their illusion powers to create illusions that will complicate escape from the prison. Many of these illusions have been dispelled overtime by touch, but some remain. Whether through accident or betrayal, the djinni, like the medusa, is now trapped in the prison it helped build.

#58: Hippogriff. The most interesting thing about the hippogriff is that they hate pegasi and will attack them on sight; I guess because the pegasi are competing for similar “flying amalgamation from mythology” category that the hippogriffs live in. We haven’t even reached the griffons yet.

Pegasi make sense as mounts for Team Lawful, so we’ll assume these hippogriffs are mounts for the twisted elves we just met. The elves are able to enter the dungeon from a non-obvious angle because they have flying mounts.

#50: Grey Ooze. These are the rock-camouflaged, armor-dissolving oozes. While I didn’t want all of our slimes to be associated with our black dragon, the grey ooze is the one that fits the best with their acid vibe. The black dragon can loogie these out and send them roaming places where it cannot go, but they're too dumb to do complex tasks, which might mean the dragon would be willing to parley with adventurers. 

World's Largest Rewrite: Rats are Terrifying, I Want to Leave This Dungeon Right Now

 #25: Crocodile. We got giant crocs, we got large crocs, we got normal crocs. In contrast to OSE sharks and 5E crocodiles, there is no unique mechanic, like a bite-and-grapple; they just get bigger and bite harder. We’ll go with the giant crocodile, as it has a bit of lore – “usually encountered in Lost World regions” – that fits with our idea that the prison has a zoo of ancient pseudo-extinct beasties.

#95: Rat. Rats are typically either a tutorial challenge for newbie adventurers, or little more than set dressing. I like that OSE treats rats rather seriously. They have five (!) special characteristics, making them much more mechanically distinct than a lot of OSE’s other animal monsters. 

• Afraid of fire. Will flee unless “forced to fight by summoner.” Their fear of fire means they are a puzzle monster; like the beetle swarm that invites the PCs to escape by diving into water, the rat swarm has built-in counterplay. We’ll decide later if these rats are compelled by a rodent-summoner, or just out there swarming on their own volition.
• Disease. There’s a 1-in-20 chance of disease, which allows a save, and the disease has a 1-in-4 chance to be deadly over 1d6 days. Given that the disease has no immediate effect, I would probably keep a rat bite tally during any encounter with rats, and sum the infection odds to a single roll after the encounter is over. The disease system here is pretty forgiving, but obviously scales in danger with the number of rats encountered…
• Pack. The equivalent of swarm rules from modern D&D. It does not specifically state how the pack feature interacts with the disease odds; I would rule that swarms have a 5-in-20 chance of inflicting disease, versus a sole rat’s 1-in-20.
• Attacking in water. Excellent swimmers, no penalty. Swarms of disease-ridden rats chomping away at a swimming adventurer is scary enough on its own, without even considering…
• Engulf. The PC saves versus death or falls prone, unable to attack until they can stand again. This is pretty scary in a land encounter. In the water… well, when your PC sinks beneath the surface, covered in ravenous, diseased rodents, no one is going to mistake that for a training wheels encounter. 

#101: Rust Monster. Another classic creature that is brutal in its old-school presentation. Magical items only have a 10% chance per “plus” to resist the effect (the entry does not say if metallic magical items without pluses even get this chance). Oof.

I like the rust monster as an invasive species, possibly drawn by the abundance of unprotected metal in the prison. Like the cellipedes, they are a kind of dungeon vermin that specifically plagues prison wardens. As much as adventurers hate rust monsters, prisoners love them, as they can quickly destroy metal cell bars, incidentally freeing the incarcerated.

So the rust monsters are hated and hunted by the guardian monsters, but beloved by the prisoners. Escaped prisoners are trying to capture and herd the creatures toward their allies, using the rusties to jailbreak those who could aid them in a more general escape from the structure.

#117: Thoul. We planned for this. Our thouls are bodyguards to the hobgoblin king! They were mutated with trollish blood, which caused runaway cellular replication; the ghoulish infection counterbalanced that explosion of life, and now these creatures live a tenuous existence, their trollish blood and their necrotic flesh caught in a delicate balance. 

#131: Weasel, Giant. Like the giant shrews before them, the giant weasels provide a surprising degree of mechanical crunch. They are tunnel dwellers who are good at tracking (favoring wounded prey) and have infravision. They attach to targets and suck blood (!), and treasure is found on the bodies of their victims, in their lair. This encounter writes itself. 

The giant weasels are invasive to the prison complex. They have burrowed down into the ground surrounding the prison, and created tunnels between otherwise unconnected areas. They show up 1-4 turns after a PC is injured, stalking the group, waiting until the PCs are in darkness, separated, or otherwise vulnerable. They then emerge from the nearest tunnel, attempting to grab a victim and drag them back toward their warren. If they succeed in pulling someone back into a tunnel, they move backwards, so that their victim’s body blocks pursuers’ line of sight. The weasel can continue to drain blood as they drag their victim to their doom. That’s a pretty intense encounter, for a superficially unimpressive creature.

But those tunnels also provide an opportunity to the PCs. Like our mother fungus, apes, and gargoyles, the weasel is not just a combat threat, but also a creature that creates an overlay on the dungeon, another network of connections that intersect and defy the built structure itself.

#55: Hawk. Not much to see here. We have normal hawk and giant hawk; they can swoop attack, and they are trainable. That’s it for OSE. The Monster Overhaul index directs us to another entry with a “why are they attacking” table, where we find “judgement-altering disease.” 

I’m going to combine that with OSE’s note that they can be trained, and use this as another opportunity to tell the story of the prison’s decline. The hawks were once kept by the prison wardens, perhaps used to track prisoners who escaped the walls and fled into the wilderness. They are now feral and have contracted some kind of illness that compels them to harry anyone who approaches the prison exterior, regardless of purpose. The brigands camped outside the prison have figured out some kind of combination of smells and colors that repel them, and have festooned their camp in associated materials (it makes them look ridiculous). 

#86: Octopus, Giant. We’re running into some overlaps as we get deeper into the OSE bestiary. The giant octopus lives in the same mechanical space as the lesser sea serpent, and we haven’t even gotten to OSE’s giant squid. The Overhaul’s index refers both to the kraken entry. Rolling there are on the variant table we get chameleonic; pulsing chromatophores. I’m reminded most strongly of the intelligent octopi in the science fiction novel Children of Ruin, who use colors to communicate in a way that the humans in the story don't understand at first. Making our giant octopi intelligent rather than yet another big sea beast could carve out some interesting space. Deeply curious creatures, they’ve been to drawn to explore the dungeon. 

#122: Triceratops. The OSE triceratops is an aggressive herbivore that charges on sight, presumptively behaving like a territorial bull. The Overhaul refers us to the same “herd lizard” category that we used for stegosaurus. Lets do something different and say that our knight Sir Guy Truthspeaker has captured a young triceratops and is using it as a mount. The other triceratops are agitated by the missing member of their herd.

#46: Gnome. The best bit in the OSE entry is “May make foolish decisions to obtain precious items.” They get along well with the dungeon's dwarves, so they fit neatly with an already-established faction. Like any good faction, some of these gnomes are on board with this whole “strip the magical prison of valuables” approach, while others recognize that this is a bad idea. The Overhaul gives us some unexpected material to work with, directing gnome-seekers to the elemental spirit category, where they are the earth/stone equivalents of nereids, sylphs, and salamanders. Rolling on the “local reputation” table, we get “the honored dead, reborn.” So the dwarves have summoned gnomes that they believe (rightly or wrongly) are reincarnated ancestors. That certainly adds an edge to the dwarves' betrayal.

#103: Scorpion, Giant. A good straightforward monster. Most OSE animals, even giant ones, are neutral, a pattern that holds true in modern D&D as well. But the giant scorpion is chaotic. I’m not sure why. It’s not because of the poison (the giant spider is also neutral). The chaotic alignment pushes me toward the idea that the scorpion was a prisoner (or specimen) in the dungeon, rather than an incidental invader. 

The World's Largest Rewrite: Diabolical Dwarves, Boorish Brigands, Sanguivore Squids

As described in my recent series of megadungeon posts, the world's largest rewrite monster series is pretty useful for generating monster ideas, so I'm returning for another batch of 10 to add to the pile. When this series is finished, we'll sift through it for the best monsters, and (if they are very good) we'll add them to our megadungeon.

 #126: Unicorn. You thought we were done with weird horses? We are not done with weird horses. 

OSE gives unicorns the “empathy with maidens” and “teleport” powers. The maiden affinity comes from myth, but I went down a rabbit hole (jackalope hole?) on the teleportation ability. It appears to originate with AD&D, possibly to give unicorns a countermeasure against players hunting and harvesting them. That would make sense, given Gary Gygax's focus on the benefits of hunting or capturing monsters.

The unicorn doesn’t really make sense as a prisoner in our dungeon-prison, and while it is lawful, it isn’t really a dungeon guardian. Rolling on the Monster Overhaul’s excellent “Dubious Methods to Lure a Unicorn” table, we get “a wounded Dryad.” The unicorn is here to help a dryad in distress. We haven’t rolled dryad yet in this series of posts, so we’ll revisit what exactly is going on when we get to that result.

#34: Dwarf. Are these dwarves prisoners, intruders, or guardians? We’ll just choose randomly, and we get guardians. OK, so a clan of dwarves is sworn to protect this place. They are comfortable underground, reasonably long-lived, and could repair structural damage to the dungeon, so they make sense for this role.

OSE suggests groups of dwarves have a leader, and we can use the Overhaul to detail this leader, and in turn, better understand these dwarves. OSE does not have dedicated entries for dwarves or other PC ancestries, but they appear under the general “adventurer” category. Rolling on the random tables there, we get “sloth” as a vice and “wealth beyond dreams” as a goal. So the dwarves delved too greedily and too... lazily. Our leader is Fingmir… Silverstone… no, no, absolutely not. Fingmir… Silverheart. He has blue and red heraldry and is a prophet (!). His specialty tool is “targeted poisons.”

The story becomes clear. The prison builders (celestials or other uncompromising lawful types) contracted a dwarvish clan to guard the prison. The dwarves’ commitment to the pact has weakened over generations, particularly as it became clear the prison builders either could not or would not deal with the progressive deterioration we’ve seen in other parts of the prison. The dwarves become despondent and lazy, and Fingmir, driven by greed, poisoned the previous clan leader, his mother, believing that she was hiding secret wealth from him. She was not. He is now trying desperately to figure out some way to get rich quick before his crimes (and lack of treasure) are revealed to the other dwarves.

#27: Dervish. The OSE bestiary is kinda wild. We don’t have time to unpack the layers of cultural misinterpretation that transformed an ancient Persian ascetic tradition to the “fanatical desert warrior”  archetype that Gygax and his successors had in mind. I guess it kinda gestures at condensing 2000 years of history, ranging form Parthian horsemen to Ottoman janissaries, into one pulp fiction stat block.

There are a few ways to do something more interesting with this entry, but I think keeping the idea of “lawful extremists” and throwing out the Orientalism is probably the easiest way to get something useful. We can use the knight entry from the Overhaul to add some new stuff in its place. The Overhaul tables give us the following.

Sir Guy Truthspeaker is a knight of middling renown who duels everyone he meets to develop his combat skills. He’s bedecked with weapons and wracked with religious doubt. His heraldry is azure, with a pale division and a lion charge surrounded by ivy.

We just had Dwarven guardians, so I'm going to make Guy and his retinue outsiders. They’ve come here on a religious quest, but Guy has doubts. Maybe seeing the state of the prison has shaken his confidence in the celestials. 

#83: Nomad. Yes, we’re rolling randomly, but as with the stone-adjacent monsters last time, the dice do like to suggest connective themes. So after an entry about dervishes, who wander steppes and deserts, living in tents, we get to an entry about nomads who… wander steppes and deserts, living in tents. We haven’t even gotten to the bandit/brigand pairing yet.

The Overhaul saves us once again. Whereas dervish was an excuse to use the otherwise-unrepresented knight entry, nomad points us to the Overhaul's barbarian category. Rolling on the random tables, we get “Dream-readers. Dour, fatalistic.” They want “Strong drink. Herbal distillations preferred.” They are led by Slagnar Urn, who is “feverish and ill, desperate.” 

So Slagnar is ready to imbibe a fatal dose of rare herbs that will take him on his dream-quest into the afterlife. He and his family are here to gather the necessary herbs. Unlike the gnolls and other intruders, they’re a much more practical faction for the PCs to cooperate with.

#119: Toad, Giant. This is the classic sticky-tongued ambush predator. We can drop them in the same general area where our other “freshwater invasive species” entries landed earlier. They dwell in a log jam in the “river” that is pouring through the roof of the dungeon, and they love to eat beetles, which they snag from the nearby swarms. The devil swine who run the area prefer human flesh, but aren’t above snacking on toads that intrude into their territory in search of beetles. 

#63: Invisible Stalker. OK, here’s a special guy. The invisible stalker is a flawless tracker and nasty ambush attacker. It has a clear fit with the dungeon theme, as a summoned creature deployed by the prison builders to track down and capture escaping prisoners. But as the enchantments that bind it have weakened, its behavior has grown erratic. The Overhaul directs us to elementals to cover the stalker. Rolling for air elementals, we get a motivation of “a sealed building or tomb opened.” So the stalker is now doing roughly the opposite of what it was originally employed, hunting guardians or aiding prisoners. We could include a random mood table, where the stalker -- if encountered multiple times -- is sometimes more cogent, completing its original duties, and other times rebelling against them.

#12: Brigand. I mentioned them when talking about nomads, so of course they showed up almost immediately. They have little distinguishing them from bandits, except that the brigands are fighter-coded, while the bandits are closer to thieves. We’ll use the Overhaul’s mercenary entry here, and worry about bandits later. 

Rolling on the mercenary tables, we get the Legion of Gold, led by William Osprey. They prize cleanliness and order! Apparently William’s astrologer-wizard started gibbering about “moondrops” and “silver rain” and ran off into the night, entering the prison in a delusional state. The mercenaries are understandably wary of following him in, but want to get him back, presumably because his magic is essential for some scheme they are pursuing.

They’re camped right at the main entrance to the dungeon. They’re more than happy to opportunistically tax adventurers coming out, or even outright steal from them (I think among the old-school megadungeons, it is possibly Rappan Athuk that is famous for brigands camping the front entrance?) Then again, the brigands could be merciful to adventurers willing to go back inside and find that wizard…

#127: Vampire. After a series of guardians and invaders, we finally meet another unambiguous prisoner. The vampire has a massive entry by OSE standards, mainly detailing all the classic folkloric vampire powers and weaknesses. Compared to some of the monsters with rather thin premises behind them, the vampire almost has too much to work with.

Fortunately, random tables can provide focus just as well as they can provide inspiration, and the Overhaul has a full three pages dedicated to the vampire. Ours is named Kirkstein, and they have a classic ruff, frills, and handkerchief aesthetic, with decadent indolence as their demeanor. Anyone who kills them is doomed to gradually become a vampire – that would explain why they were imprisoned instead of destroyed. They possess a sublime charm that makes them difficult to attack unless they are already hostile. Their favored follower is a giant albino snake!

#5: Bat. It keeps happening! Themed back-to-back monsters. We want our giant bats to hunt our giant beetles, so we’ll place them in the same region. Both the OSE and Overhaul entries are pretty minimal, but the latter gives us “pushing prey towards a cliff” as a reason to attack. The lefthand edge of our prison flowchart features a lot of wildlife and cave-dwellers, so there must be a broken precipice where the bats are chasing giant beetles, driver ants, boars, and the occasional terrified kobold over the edge, then eating them after they die from the fall.

#104: Shrew, Giant. In terms of monster detail, the humble shrew is quite a lot closer to the vampire than the mechanically generic human subtypes. Click that link and see how much this guy has going on. In summary:

• Insectivore 
• Burrower
• High morale (most beasts have 8; the shrew has 10)
• High movement (180/60, similar to a wolf!)
• Always wins initiative in the first round
• Ferocious; creatures with 3HD or less have to save or run away (the shrew itself is only 1 HD, but bugbears and harpies are fleeing in terror before its shrewful presence)
• Territorial 
• Echolocation 

OSE does not even mechanically apply the venomous saliva that allows some real-world shrews to paralyze their prey! You're leaving money on the table, OSE!

As burrowers, the shrews also help us create dungeon connectivity and emphasize how the space has changed from its original usage. I’ve recently been reading through Demon Bone Sarcophagus, which also demonstrates how a burrowing animal (in that case, a giant sloth) can provide navigational complexity that breaks up a very orderly, grid-based, built environment. Our shrew tunnels will be a useful navigational hack, but also dangerous for low-level characters to exploit; you do not want to get caught trespassing in these tunnels by a gang of ferocious, brave, fast, echolocating shrews.

The World's Largest Rewrite: Trepan Lizards, Grues, and Carving Up the Stone Theme

Last time: Grey Horse, Devil Swine, and Normal Humans

#109: Skeleton. We’ve already met our mummies, zombies, wraiths, and wights, so we have a pretty good number of undead knocking around the prison. Skeletons, like zombies, make sense as minions of more powerful undead. We placed the zombies with the mummies, but let's save the skeletons as servants of an as-yet unseen monster. I’m going to place them near the salt water aquatic monsters, to provide some variety there. The bones of failed escapees, animated by some dark magic, drifting up from the depths amidst the seaweed, to clutch at ankles, join us, join us... 

#132: Whale. Yeah, OK, let’s do this. OSE includes a killer whale (AKA orca), narwhal, and sperm whale. Rolling randomly gives us the sperm whale. A brief aside: It is interesting to see how OSE stats suggest a different concept of the world than a modern D&D system. A sperm whale has 36 HD and 162 (!) HP. A red dragon, the strongest of the chromatic dragons, has 10 HD and 45 HP in OSE. 

Compare that to 5E.2014, where an adult red dragon has 256 HP. The 5E MM doesn’t stat whales, but the roc is similar in HD to the whale in OSE, and that is about even with the dragon in 5E. It feels like modern designers felt it was important that the dragon was not only the most dangerous monster, but also (among) the biggest monsters. No such compunction in OSE.

The sperm whale is so big that it is hard to place it in the dungeon; it is very much intended as a wilderness monster. So let’s embrace that idea and put it outside the dungeon, but strongly associated with it. The sperm whale’s signature abilities are to ram ships and to swallow creatures whole. The prison builders enchanted this creature to crush ships approaching the island prison, and swallow any survivors in the water. Their intent was to prevent both prisoner escapes and rescue attempts from the outside. The whale itself can serve as a mini-dungeon, with survivors living inside the whale; that’s a classic trope. 

#41: Gargoyle. The flow of water is already a consistent theme within this dungeon, so let's include gargoyles that honor the origin of the term. Historically gargoyles were not just statues (or “grotesques”) but specifically rainspouts on the buildings they adorned. Our gargoyles are bound by the dungeon builders to channel water through the dungeon, for hydration, drainage, and sanitation purposes. They may be cruel and twisted monsters otherwise, but their commitment to the routing of water takes priority over monstrous behavior. Two gargoyles can form a 1’ diameter “pipe” through solid stone between their locations. PCs who parley with them could use their help to bypass various hazards and obstacles. Beware their betrayal, however, as they could easily send you trouble instead.

#115: Stegosaurus. The OSE entry for the stego is minimal, but the Monster Overhaul, as usual, proves its value with supplemental random tables. Rolling on a few of those we get “fleeing a predator” as a response to the prompt “why are they charging?” and “we steal and devour their eggs” to answer “what do we use them for?” We’ll place these guys near the sabre-tooth tiger, since they also fit the lost world theme. But we also want to build up the idea that the dungeon’s divisions are breaking down, and that creatures from different regions are interacting with each other. So we’ll say these stegosauruses are frightened by the chimera, and that the noble and his retinue are stealing and eating their eggs.

#23: Cockatrice. It is interesting that cockatrices and basilisks, at 5 and 6 HD respectively, are quite a bit bulkier monsters in old-school D&D, while modern D&D presents them as relatively junior monsters, compared to the medusa and gorgon in the Family Stone. The cockatrice is described by OSE as “small,” but is about as tough as an ogre. The monster overhaul notes they are “rarely viscous, though their feeble minds and tendency to panic can lead to disasters” (this also serves as a good description of my cat). As discussed when we placed our medusa, petrification is an incredibly useful ability for the fantasy prison warden. Petrification can be a way of safely transporting a prisoner; putting them in “solitary”; managing a shortage of supplies by temporarily (unless…?) reducing the percentage of the prison population that needs to, you know, eat; and even creating statues that can fit together to build walls. You know, like in Unico in the Island of Magic.

Uh, you know, Unico in the Island of Magic? OK, maybe not everyone has seen Unico in the Island of Magic. You can watch it on Youtube! The petrified-people-used-for-building stuff starts around the 30 minute mark. I watched this when I was very, very small, and for years afterward, I had a very deep and paralyzing fear of being turned into a statue and used as building material. Fortunately, this never happened to me in real life, and I eventually got over that fear. But this probably does explain why I have written about gorgons so much on this blog. These blog posts don’t typically include processing childhood fears, but there ya go.

What were we talking about? Oh yeah, the cockatrices are here for the same reason the gorgon (medusa) is – petrification is really useful to the prison builders. For the same reason I don’t want to cluster all the undead together, I’m not going to put the cocatrices next to the other petrification creatures. I’ll drop them near the center of the map, next to the doppelgangers, who were the second-ever monster we placed during this exercise. If the cockatrices petrified the doppelgangers, they might have formed a feral colony near that area. The zombies are unaffected or indifferent to their presence, and the bull sharks are protected from the stony birds by water. 

#4: Basilisk. What a serendipitous result. We have our oops-all-rocks enemies showing up back to back. In Soviet Russia, rocks pet you. 

Combined with our gargoyle in this entry, and our gorgon (medusa) lore, I think we have some interesting ideas of how petrification played a major role in the formation and maintenance of the dungeon. I like the idea that the prison-builders started with cockatrices (relatively easy to control, insofar as they have to make physical contact to petrify). Later, as the prison grew both larger and more difficult to control, they added basilisks, in a desperation move (capable of petrifying at range, but a real double-edged sword for other sighted creatures).

Rolling randomly, I’m gonna put the basilisk on the left side of the map, and it lands right next to the… rock baboons… which feels like the dice trying to tell me something. We’ll keep our scream-oriented baboons but also make them literal rock baboons. Why not? 

#15: Bugbear. Another minimally described goblinoid in OSE. Hairy, ungainly, attacks with surprise (this also serves as a good description of my cat). Going to the Monster Overhaul directs us to the… ogre entry, surprisingly, but I respect it. The Overhaul is not afraid to create Weird Problem Creatures, and the bugbear is definitely one of them. Its abilities are as follows: “Harmed by innocence. Attacks against the [bugbear] take a penalty equal to the attacker’s HD or level. Bonuses to damage become penalties. Toy swords cut as steel ones.”

That’s kinda mental, right? Certainly more interesting than “stronk goblin with +2 to surprise, move along.” You can imagine why a creature that fundamentally subverts violence would end up in our prison. However, by imprisoning this freak amongst mostly guilty inmates, the jailers have inadvertently made him powerful. None of the twisted reprobates in the prison would be able to harm this guy. I’m not trapped in here with you, you’re trapped in here with me. This is a cool puzzle monster. Clearly our bugbear is a dungeon boss, like the dragon and the devil swine, controlling other monsters/NPCs, because they cannot harm him. We’ll drop him near the bottom of our diagram; he’s probably bossing around some combination of hobgoblins and humans. Maybe the poor cyclops too.

#69: Lizard Man. The most evocative bit from OSE is obviously “Man-eaters: Kidnap humans and demihumans, whose flesh they regard as a delicacy” (thankfully, this does not serve as a good description of my cat). 

To my surprise, there is no entry for lizardmen in The Monster Overhaul. Not even an index entry pointing to another monster. I guess lizardfolk fall somewhere between kobolds and troglodytes in the Overhaul taxonomy. We’ll use troglodytes. With four separate random tables, they have enough going on in their entry that there will be material left for the actual troglodytes when we eventually roll them up.

Rolling a few times, we get “Genetic offshoot blessed with strange powers but cursed with mind-rot” and “Trepanning drill. Improves divine access” as a treasure. These two hooks together really sell these guys. The basic OSE beastiary does not have a direct mind flayer equivalent, so for this dungeon, our lizardfolk fill that roll.

#105: Shadow. “Intelligent, incorporeal (but not undead) monsters that look like shadows. Able to slightly change their shape.” I like the non-undead shadow concept. The Overhaul’s index suggests “Grue” as an interpretation, which isn’t on our OSE list, so we’ll use that to embellish these fellows. The grue is a highly mobile, durable, deadly creature in darkness, with light as its only weakness. It is easy to imagine our prison wardens trapping a grue/shadow here with redundant “walls” of light. As the prison keepers' authority slips away, the lights begin to go out, and the grue probes its containment, restless to be free. We’ll probably create a “high security” block for creatures like this, that require special methods to imprison. 

#45: Gnoll. Gnolls have a little bit more going on than some of the other humanoids, but not much; the OSE description is just a winking reference to their post-Dunsany presentation as a portmanteau of gnome and troll. The Overhaul has no gnoll entry, but refers to the hyena entry, which has a nice “legendary abilities” table. “Hyenas only eat the corpses of unholy people. The souls of those they consume stay inside the hyena.” This gives them a pretty clear reason to show up in our dungeon. The gnolls have broken into the prison in search of "unholy" souls to devour. We’ll assume they’ve entered the prison from the top and are trying to get toward the lower middle, where the humans are.

Here’s our updated diagram. Getting a little more crowded, isn’t it? Remember, this is not the dungeon map; just a very simple diagram that can eventually inform regions, which can in turn serve as the basis for an actual map.

The World's Largest Rewrite: Grey Horse, Devil Swine, and Normal Humans

Last time: The World's Largest Rewrite: Floating Heads, Mother Fungus, Cellipedes

#60: Horse. OK, yes, I jumped into this exercise without really thinking about how to handle the various mundane “monsters” in the OSE bestiary. I don’t want to overlap with mules and camels, so I’m going to dive deeper into the Monster Overhaul, my manual of choice, to populate this one.

The book includes an entry for a “grey horse,” a strange constructed thing in the shape of a horse that challenges travelers to make clever rhymes, eating their rations as punishment if they fail. The grey horse seems too benign to be a prisoner, and too capricious to be one of the jailers. I’ll treat it as an invasive species, but without explaining how it got here (the grey horse just shows up in places where it is not wanted).

#84: Normal Human. Ah yes, the most dangerous monster of all; the Normal Human. OSE defines them as “Non-adventuring humans without a character class. Artists, beggars, children, craftspeople, farmers, fishermen, housewives, scholars, slaves.” But they are also implicitly not bandits, or pirates, or nobles, or any of the other “monster” types in the OSE bestiary that are obviously humans, but have their own entry. Essentially this is what the modern game would call a commoner.

I think we have some Normal Humans here who are guilty of Abnormal Crimes. They’re probably not individually dangerous to adventurers; even the typical serial killer is more of an opportunistic-but-ordinary person, rather than someone with high levels as an assassin or something. These Normal Humans are like the prisoners in Con Air or the mooks in the Batman Arkham games. They are weak, but numerous. And they likely have some powerful leaders among them as prison bosses; maybe NPCs with classes, maybe actual monsters.

#106: Shark. Shark!! The shark brings us back to the submerged section of our dungeon. We want to distinguish a bit from the other monsters that have flooded (literally and figuratively) into the prison. Picking randomly among OSE’s three sharks, we get the bull shark, which can ram and stun prey for three rounds. This is a nice twist that you don’t really see from beasts in modern D&D. I like the idea of the bull sharks ramming prey as they pass through a transitory space like a submerged hallway. The hallways are navigable for the sharks but too narrow for the sea serpent, who is the alpha predator in the seawater sector. Stunned swimmers sink deeper into the depths, so attempting to rescue them presents further risk for their allies. The crabs clean up what the bull sharks don't eat, at the bottom of the halls, amongst the bones of failed prison escapees.

#70: Lycanthrope. I usually choose a subtype randomly, but in this case I am going to simply pick the devil swine, because (a. they’re much more evocative than the other, more standard lycanthropes, and (b. they’re evil, so they’re the easiest to explain as prisoners of celestials. OSE describes them as follows: “Corpulent humans who can change into huge swine. Love to eat human flesh. Lurk in isolated human settlements close to forests or marshes.”

A devil swine has 9 HD (!) and a charm ability. So these guys are not minor brutes, but instead dangerous bosses, and with their charm ability, probably a powerful faction in their own right. I imagine they’ve been strategically charming other prisoners to take over the prison and eventually try to escape. Relative to some of the other very archetypal monsters we have featured so far, “shapeshifting mind-control pigs” could really surprise players.

Another nice detail on lycanthropes is as follows: “Horses and some other animals can smell lycanthropes and will become afraid.” The grey horse and the mules are both aware of the devil swine and could help the players avoid them, or at least anticipate their presence.

#22: Chimera. Another folklore classic. OSE doesn’t provide any suggestions beyond a visual description. The Overhaul gives us more to work with, including a roll table that produces a chimera with a goat for the left head and hindquarters, a leopard for the center head and forequarters, and a newt for the right head and tail. It breathes poison gas and has no wings. Created by a wizard who is also probably interred here.

#26: Cyclops. It’s interesting to compare the OSE cyclops to one from a more modern-style monster manual. The OSE version hews close to the Odyssey; it raises sheep, is slow-witted, and possesses the ability to curse people. All straight out of the Greek lore.

The 2014 5E monster manual, by comparison, shunts this information into the flavor text, abstracting it away from the source myths. Consequently, aside from its poor depth perception, the 5E cyclops has almost nothing to distinguish it from the statistically similar hill giant, which is a shame, particularly because 5E has an abundance of interchangeable brutes like this taking up space in the book.

The Overhaul parsimoniously groups the cyclops with the giants, so we’ll roll there to get some more of an idea of what to do with this dude. The “Why fight these giants?” table produces “They keep growing larger. Soon it won’t be possible to harm them.” So this cyclops was getting bigger and bigger with no end in sight, and the magic of the prison keeps that magical growth in check. The cyclops may even be a willing prisoner here, worried that the prison’s weakening structural integrity will reboot their uncontrollable embiggening.

#7: Beetle, Giant. The fire beetle (a fantasy firefly) and the oil beetle (a fantasy bombardier beetle) are the famous ones here, but rolling randomly tilts me toward the Tiger Beetle (a fantasy… uh, tiger beetle). OSE tiger beetles “hunt robber flies, but sometimes eat humans.” The bit about robber flies is useful, as we haven’t placed those guys yet.

The real-life tiger beetle has a number of gameable features we can steal, including antlion-like larvae that burrow into the sand to trap prey; an ability to charge very quickly toward prey, but with the need to stop and visually reorient; and the ability to mimic the sounds of toxic moths so that bats won’t eat them. We can tie these guys to both the robber flies and the bats when we get those results. 

#100: Rock Baboon. Once again I’m charmed by old-school D&D’s “animal, but slightly weird” approach, contra modern D&D’s harder division between mundane animals (lumped together in the back of the manual) and fantastic monsters. The rock baboon is a pretty straightforward monster per the OSE entry, but I do enjoy that they “communicate with screams.” Same, rock baboon, same. How far can we take that? 

Perhaps relative to other creatures in the dungeon, the rock baboons are particularly good at communicating important information over relatively far distances. The primary danger when encountering a single baboon or a small group is that they will alert the rest of their troop, even if they are far away. The baboons could even be useful allies if befriended, facilitating long-distance communication (filtered through baboon-speak, of course).

#134: Wolf. The most interesting bit about wolves in the OSE entry is that they can be trained, and that goblins ride dire wolves. So we have two possible routes here; wolves trained by the wardens to police the prison, and wolves ridden by the goblins we haven’t seen yet. The next entry better serves the prior option, so I’m going to go with the latter and assume these are goblin-affiliated wolves. We’ll put the wolves near the hobgoblins and leave the door open for a greater goblin zone in the prison.

#10: Blink Dog. Apparently we’re in the dog block. In addition to their signature teleport ability, blink dogs are lawful and hate warp beasts. I think it makes sense to consider them servants of the jailers. Their blink ability would make them well-suited to capture, corral, or pursue prisoners without the prison’s physical barriers limiting their movement. Perhaps they’ve been left to their own devices since the prison has gone to rot. A first encounter with the blink dogs will probably involve them shadowing PCs or observing them from afar to take their measure. They could be powerful allies for PCs who earn their trust by containing monsters or stopping escapes.