Last year, one of my favorite science fiction authors, Richard K. Morgan, published his first fantasy novel, The Steel Remains. If I hadn’t already read enjoyed his previous novels, I would have gotten it based on the Amazon “look inside” preview alone (Click the link above to get to it).
If you don’t have the patience to read all that, you should; the prose that leads up to the reveal is worth it. But if not, here’s the gist: the undead that have attacked the village are corpsemites, which are semi-intelligent slugs that use human corpses to get around, find one another to reproduce and perhaps even enjoy pantomiming human life.
The undead are not a part of Morgan’s fantasy world; corpsemites are an ingenious reinterpretation of the walking dead that would work great in a campaign that does not use by-the-book undead. These only appear in the scene at the beginning of the book; sometimes the throw-away ideas an author uses can be put to good use in an RPG. I’ve created stats for them below with a combined Labyrinth Lord/Swords and Wizardry statblock. I made up the details of their lifecycle. He might have other, better ideas for it.
Corpsemite (from The Steel Remains by Richard K. Morgan)
No. Enc. 1-4
Movement: 120′ (40′) inside host; 30′ (10′) outside
[S&W Move 12 inside host; 3 outside host, 9 in combat]
Armor Class: 7  inside host; 4  outside host
HD: 2 for host corpse, 1 for slug
Attacks: 1 inside host; 1 outside host (1 grab OR 1 bite)
Damage: 1-8 or by weapon inside host; grab = entangle + 1d4 acid damage; bite = 1d6 + save or die
Special Defense: If inside host corpse, the corpse will take damage before the slug.
Hoard/Treasure Class: None
Challenge Level / XP: 5/240
Corpsemites are slugs that burrow into humanoid corpses or living hosts. Once inside, they use the host to walk, find food and eventually corpsemite mates. They appear as long, bluish/gray slugs with many long tendrils extending from their body. They mouths are round and full of small razor-sharp teeth used to eat through flesh, coffin wood and dirt.
They begin as eggs laid inside a corpse or in a hole dug in a graveyard or charnel ground. They hatch fully developed and use their keen sense of smell to find rotting flesh. Their skin excretes an acidic slime that helps them tunnel and eat through coffins. Once inside a host corpse they will feed on any remaining nutrients in the flesh until, only a few days after hatching, they are full grown adults. The corpsemite will then dig out of the coffin and up through the ground. Once outside, the mite will use the body to eat offal, carrion and garbage.
Corpsemites stick with their broodmates for most of their adult lives. Adults tend to move from host to host, always preferring the freshest corpse available. Sometimes adult corpsemites will spar over a fresh corpse, much as hermit crabs spar over shells. If necessary, they will attack and burrow into a living host, killing it in the process. Near the end of their year-long lives, they begin to look for a mate, preferring, but not requiring, a mate from outside their own brood. Corpsemites are hermaphroditic, but unable to fertilize their own eggs. Mating occurs while inside the host corpses and appears just as you think it would: slime-covered corpses having sex.
Corpsemites are protected by the host corpse, which takes 2HD damage before the mite will abandon it. Somehow the mites are able to tell from muscle memory how to wield any weapon the corpse might have with it.
Outside the host, the mite is agile and can move quickly for short periods of time. They can leap from a host to an opponent, entangling him with tendrils (save vs. paralysis or lose movement next round). The skin of the tendrils has an acidic slime that causes 1d4 damage to skin or armor. The corpsemite’s bite as an attempt to burrow inside its victim. The bite does 1d6 damage and the victim must save vs. death or the mite will successfully enter his body. Failure means the host will be fully under control of the mite in 1-2 rounds and dead 1d6 rounds afterward. A corpsemite can be removed from a living host via cure serious wounds or regenerate spell, provided the spell is applied after reducing the host’s HP to zero but before his consciousness has left the body.
Some believe corpsemites are maggots possessed by demons; others say they are the snot of Baba Yaga, spat down to earth to torment the living. Corpsemites are not widely known or understood, and most uneducated populations will believe them to be the dead returned. In lands where cremation has long been the custom, Corpsemites are rare. In lands where cremation is introduced as a means of means of stamping them out, corpsemites will look for living hosts instead.
Corpsemites were created by Richard K. Morgan and are presented here with permission from the “obscurely flattered” and very righteous author, for use inside your own personal campaign only.