Deathlock

Deathlocks are undead spellcasters reanimated from the corpses of warlocks. Deathlocks are created when a still-living warlock fails their patron (usually by dying), or risen by necromancers to bolster their command over undead minions.

Description
Most deathlocks are resurrected with the intention of continuing their former goals, or to reinforce a necromancer's ability to control undead. As a result they typically retain their memories and freedom-of-self, though are completely bound to their animator's will.