Large and strong demons from DOOM that throw green fireballs and melee the player. Possessing pale skin, brown curled horns and the lower body of a goat. Initially introduced in Doom II, Hell knights were originally just a recolor of the Baron of Hell with half as many hit points and otherwise identical combat characteristics.
From Doom 3 onward, they take a grislier appearance. The horns are gone, the upper half of the head is exposed bone, the mouth's muscle tissue is exposed, and they look to have grown armor and lost any of their fur.