Hell Knight/Doom 3

The Hell Knight is a powerful demon in Doom 3.

Physical appearance
The Hell Knight is huge and very muscular. An in-game examination of its spine indicates it has a massive skeleton. It has no visible nose, and its deformed ears resemble a human's, fused to the sides of its head. Its obscure eyes are very small and black, located on the sides of the head just above the mouth. It is easily the largest non-boss enemy in the game. Assuming the Marine is 6 feet (1.8m) tall, the Hell Knight stands about 10 feet (3 meters) tall.

In Hell, Hell Knights show a different appearance from those on Mars. Their skin is greyish-green and some parts, such as the mouth, upper chest, hands and feet, are red, possibly soaked with blood. They are covered with scars and demonic runes, and have a pentagram on their forehead.

While the classic Hell Knight has horns and hooves, being meant to resemble a satyr or minotaur, the Doom 3 Hell Knight somewhat resembles a huge muscular skeleton or an alien. The head of the Doom 3 incarnation of the Knight is somewhat similar to the Shambler from the first Quake.

Two of these massive monsters make their introduction in a cutscene (obviously mirroring the debut of the first two Barons of Hell as sub-bosses of Doom 's first episode) in which the marine arrives at a teleportation room where he witnesses the portal to Hell being opened under Malcolm Betruger's supervision. A biosuit-clad scientist emerges from it, followed by a huge Hell Knight right behind him. The scientist pleads for his life, but the Knight grabs and throws him violently against the machinery of one of the portal generators, presumably killing him; a second Hell Knight comes out from the portal and then both monsters charge towards the marine.

Combat characteristics
The Hell Knight's attacks are similar to those of the Imp's: it throws fireballs at long range and substitutes to clawing attacks at close range, but it lacks sudden leaps and its clawing attacks are much slower, which gives the player enough time to dodge. However, it has a biting attack, which gives it a farther reach than it's clawing, and the green plasma balls it throws are much larger, more powerful, and have a wider area of effect, making them more dangerous in enclosed spaces. However, its ranged attacks are somewhat easier to dodge, as the Hell Knight's height means they are launched from farther up, making it possible to literally run under them.

The Doom 3 Hell Knight is actually tougher than the original Hell Knight, having almost as many hitpoints as the original Baron. The Doom 3 Hell Knight takes six direct rocket hits to kill, while the old Baron usually took five (depending on the random damage rolls). It is probably for this reason that there is no Baron of Hell in Doom 3; the Hell Knight fills the role. Essentially, rather than being the new version of its classic namesake, the Doom 3 Hell Knight is the reinterpretation of the original Baron of Hell.

Tactical analysis
When facing a Hell Knight, it is strongly recommended to use the Soul Cube or the BFG if it is necessary to take them down quickly, for they can absorb large amounts of damage. But if the situation permits, the rocket launcher, plasma gun, chain gun and even the shotgun are effective enough.

The Hell Knight, despite being powerful, is also quite slow with it's attacks. You can easily get up close range and unleash your shotgun couple of times while actively dodging it's clawing attacks. However, be careful as Hell Knights can also bite, which allows them to hit you further than it's claws. It is also a very bad idea to retreat from one when he's about to throw an energy ball, as its splash damage radius is rather large, and it is recommended to avoid being in close proximity to walls or other solid objects.

Hell Knights hang tough, and it can take 100 rounds or more of Machine Gun fire (almost 2 full magazines) or close to a full magazine of Chain Gun or Plasma Gun fire to kill one (somewhat less if you can score consistent headshots, which is relatively easy due to the Hell Knight's slow speed and huge head). The Grabber is a relatively effective weapon, however it requires 5 direct volleys from and back at the Hell Knight to vanquish it. The super shotgun is also relatively effective, provided the player has sufficient space to keep dodging, firing and reloading.

UAC research notes
These notes can be downloaded to the player's PDA during the course of the game:

Specimen 31 - Hellknight (partial)

''The cranial mass of this bipedal specimen indicates that it is one of the largest creatures inhabiting the site. Overpowering its prey with sheer might, the Hellknight is one of the most ferocious predators known to our researchers. Like the imp, this creature is able to defend itself at long-range with thrown plasma projectiles.''

Doom Resurrection
The Hell Knight is a boss in Doom Resurrection in the fourth chapter, inside the Delta Labs. Its only attack is to throw green energy balls at the player, which can cause quite a bit of damage. They can be dodged like a usual Imp's energy ball. After draining its energy bar, it will push the player into the hellgate to end up being send to hell.

Trivia

 * The first Hell Knight's appearance was in Delta Labs 4. The portal to hell activates, and two Hell Knights emerge. They also have noticeably more health than the regular Hell Knights fought later in the game, having about 1400 health, compared to 900 health for a standard Hell Knight. This makes the two of them something of a boss encounter, reminiscent of the first bosses in the original Doom, where the player must defeat a pair of Barons of Hell at the end of Knee-Deep in the Dead.
 * The Hell Knight is often said to be the scariest enemy in the game for many reasons. Aside from it's high hitpoints and damage, the beast is one of the tallest enemies in the game. It also has an unsettling visage and growl and makes the screen tremble when it walks.
 * Interestingly, if one uses the noclip cheat, a stream of saliva can be seen running from the Hell Knight's mouth.
 * The Cyberdemon is much larger than a Hell Knight but, interestingly, it does not make the screen shake when it walks.
 * Hell Knight is featured on the cover art of the game.
 * The 2016 version of the Hell Knight’s model is based on the Doom 3 version, though its body has partially exposed body parts in comparison to the Doom 3 one.