pain elemental
Floating demons from DOOM with an appearance and shape similar to Cacodemons. Brown, one-eyed, sharp teeth and distinguished with having red sclera and arms. They infinitely throw Lost souls at the player as long as the player is in sight. Uniquely lacks a corpse when killed in Doom II, and cannot be resurrected by Archviles.
In Doom 64, their appearance changes rather drastically but functions the exact same.