Mancubus

The Mancubus (plural: Mancubi) is a monster introduced in Doom II MAP07: Dead Simple, where the player is forced to fight a group of them to break through a fortified area controlled by the enemy.

Doom RPG
In Doom RPG, the Mancubus appears as a class of monster. There are three variations, identified by color: This monster class is weak against rockets.
 * Behemoth (blue with red eyes)
 * Mancubus (normal colors)
 * Druj (red)

Trivia

 * It was clarified on September 2012, that the creator of the Doom series John Romero told us what the Mancubus actually says when it attacks in Doom: II. Shouting out "MENABLANAHBLAH!"
 * There are many origins to the name of the Mancubus. It is derived from two medieval demons. "Succubus", a female demon appearing in the dreams of men, and "Incubus", a male demon who would prey upon women who were alseep. "Manducare", Latin for chewing, devouring, or eating and lastly "Mancus", referring to being crippled or missing limbs.
 * The reason for the Mancubus in Doom Eternal resembling their original 2D sprite, rather than the variant from Doom (2016), is possibly because these are the adult version. The Mancubi encountered on Mars were likely the larval stage of this demon. This could explain why their armor is carapace-like, along with the size-difference between both games (the 2016 version appears shorter in height).