The Hell Knight is a monster introduced in Doom II. It is very similar to the Baron of Hell, except that it has half as many hit points, its palette is shifted so that it has brown instead of pink skin, and it has slightly different sounds.
Killing a Hell Knight uses similar strategy to fighting a Baron of Hell. However, because of their reduced hit points, the shotguns are more effective.
The Doom II manual describes the Hell Knight as follows: "tough as a dump truck and nearly as big, these Goliaths are the worst things on two legs since Tyrannosaurus rex". In Ultimate Doom's manual, this was originally the description used for the Baron of Hell.
The Hell Knight appears in Doom RPG as a variation on the Baron of Hell monster class. As in the original, it is not as powerful as the Baron, but is more powerful than the new "Ogre" variation.