Devolved human cannibals are dungeon staple, because let's face it, they're awesome! Political refugees, rogue nobles, rebellious serfs, cults, bandits and the like are other top choices.
The Ulu and Rog cannibal tribes
These are two tribes of devolved, human cannibals, descendants of the prisoners (and some guards) of the long abandoned panopticons; they have become extremely ferocious in order to survive, and raid the surface at night to seize mates, supplies and loot.
Both groups are albino, have Blindsight, are vulnerable to radiant damage, and suffer disadvantage in bright light. They also can go berserk with bloodlust, and smear themselves with blood (carried by their priests in waterskin bags) before battle.
The north tribe (the Ulu) is allied with the Bandit King, the wererats, and the gnolls, mostly out of desperation.
The south tribe (Rog) is more powerful, and was on verge of wiping the Ulu out, until they gained new allies. The north tribe makes an ululating war cry, while the south tribe barks out a chant of ‘Rog!’, hence their names.
Ulu cover themselves with raised circular welt tattoos, the Ulu with raised zig-zag line welts. The Rog also brand themselves with garlic cloves, to flag allies and keep the roaming vampire Ilyas at bay when he decides to go for an evening walk for snacks.
Both tribes conduct ritual sacrifices to Atul, their demigod, a bastardized version of Saint Aethelwulf. They use poison darts and poison blades in battle (the poison is bought from the Myconids, and is fungus based). So much poison in this dungeon! Cooking the flesh of those so slain in a fungus sauce neutralizes the poison for consumption. Otherwise, the flesh is rendered poisonous.
Both tribes have shamans who can cast darkness.
The cannibals all charge into battle with no fear and swarm over enemies. Both men and women fight. Even their kids, at age 10, join in, stabbing at legs and feet, or yanking away gear, spell books, and equipment.
Feral pigs are bred in panopticon pens, fed with fungus, offal, dung and fresh dirt bought from Myconids, in exchange for extra corpses and spells.
The Ulu and Rog hate magic-users, for the Eldritch Veil (a rogue wizard sect) experimented on them. They can smell the magic-ether on spell casters, and will kill them immediately.
Each tribe is led by a Great Waldun (warden), who holds the Sacred Sun Key, and believe that when they die they are absorbed into The Light Above. Those who come from the surface are seen as fallen angels, demons, that must be vanquished and eaten.
Exceptions to the rule are made for the bandits (because the Ulu needed their help), who are regarded as Holy Messengers of the Sun. That doesn't stop the Ulu from eating them should they wander off alone.
