Huecuva

The Heucuva is an obscure undead monster hailing from the realms of Dungeons & Dragons. It can be thought of as the clerical equivalent to the Death Knight; a skeletal undead created when a divine character (originally a cleric, but 3e added paladin, druid and monk to the victims list) angers their patron deity through acts of heresy. Most heucuvas are created from fallen priests of good or neutral deities, but an evil priest who angers their deity through incompetence or attempts to seek redemption.

Unlike the Death Knight, or the Clerical Lich, the Heucuva is not a particularly great threat. They retain only dim memories of their former lives - enough to instinctively possess a hatred of living priests and to create lairs in grotesque mockery of true shrines and temples - and minimalistic intelligence. They cannot speak, and can only make simplistic, short-lived plans. They do possess an innate ability to cloak themselves in an illusion of being a living being, but using this to lure a victim in close is about as much as they can think of doing. They are, however, heavily resistant to turning, and their clawed fingers spread a rotting disease... worse, in third edition, unlike in AD&D, heucuvas can still cast divine spells; they're not great tactical users of their spells, but that spontaneous barrage of Inflict Wounds spells can be killer. 3e heucuvas are also heavily resistant to physical amage not inflicted with silver weapons, which does give them a necessary boost.

Unlike the lich and the death knight, the heucuva never really caught on, perhaps because it spent most of its existence as just a tougher skeleton with a diseased claw attack and a "gotcha!" gimmick. Even ion 3rd edition, when it gained spellcasting, it just wasn't really really that interesting; clerical liches offered far more versatility and power, so they were better bang for the DM's buck.

Heucuva's first appeared in the Fiend Folio for Advanced Dungeons & Dragons 1st edition. They were updated to 2nd edition in the Monstrous Compendium Volume 2 before being ported to the Monstrous Manual. In 3e, they returned as a template in the 3e Fiend Folio, but also made appearances in issues #86 and #94 of Dungeon Magazine..