From Quake Wiki
"This particular canned meat tends to open you up instead." The Death Knight (also known as the Hell Knight) makes his first appearance in The Crypt of Decay. Often seen patrolling, he makes low hoarse grunts, rather than growls, which can be identified from a distance. Distinguishable by his horned helmet, armor, and sheer size, a new player may hesitate on initiating combat with the Death Knight.
Wielding a rather large sword, and possessing a strong tenacity for charging while swinging, it is a good idea to keep your distance, though you risk him utilizing his magic missile attack, which fans out horizontally making dodging a bit difficult. Thankfully due to this, you can lure the Death Knight into inciting chaos by harming other monsters.
Some players however criticize them as being a bit too boring, lacking significant variety or threat in their behavior, and acting as a super shotgun sponge to reduce ammo and slow the player. They may appear in hordes, but that generally mitigates the effectiveness of their magic, and makes them susceptible to explosives. A far more dangerous variety can be found in DarkPlaces Mod where the magic homes in on the player and pursues rather relentlessly.
"Player was slain by a Death Knight"
|Monsters from Quake|
|Chthon | Death Knight | Enforcer | Fiend | Grunt | Knight | Ogre | Rotfish | Rottweiler | Scrag | Shambler | Shub-Niggurath | Spawn | Vore | Zombie|