This page contains tropes for the unique characters, enemies and boss-monsters of Doom 3. For tropes relating to characters of the classic games, see Doom. For those found in DOOM (2016) and Doom Eternal, see DOOM (2016).
In Doom 3: Resurrection of Evil, yet another new marine takes up the mantle of Doomguy, this time a marine Engineer exploring Mars as part of an expedition to try and figure out just what Betruger actually did. Discovering a demonic Artifact that Betruger attempts to use to generate a second invasion, he fights his way into Hell and slays Betruger, stopping his plans cold.
In Doom 3: The Lost Mission, the player takes up the role of The Bravo Marine, the sole survivor of the massacred Bravo Team that Doomguy found in the Enpro Plant. Tough enough to survive the carnage, after being dragged through a vent into a different part of the Plant, he fights his way up to Exis Labs, where he travels into Hell at the behest of the surviving scientist Dr. Richard Meyers. His mission: to destroy a teleportation platform that was drawn through the dimensions, which could possibly be used to invade Earth from Hell.
- Action Survivor: Due to the games' restructuring to a more actiony Survival Horror setting. They do have military training, but the game makes it obvious that military training will not prepare you for an invasion by Hell (as demonstrated by other Marines).
- Badass Normal: All of the demons have superhuman strength and toughness,note and they have various other powers depending on type like short-range teleportation, regeneration, flight, telekinesis, generating force-fields, or hurling energy blasts / fireballs. All of the PCs have... guns. Pretty mundane ones, too. Of course, the PCs prevail, killing thousands of demons and stuffing the invasions. Not even twenty-foot tall cyborgs slow them down much.
- Heroic Mime: In typical Doom fashion, they never speak beyond Voice Grunting.
- Hyperspace Arsenal: Carries a pistol, machine gun, shotgun, a chaingun, plasma gun, rocket launcher, chainsaw, grenades, flashlight and Soulcube on him all at once. Resurrection of Evil adds the Grabber Gun, double-barrel shotgun, and Artifact. If you change weapons while standing in front of a mirror, they'll simply pull the new weapon out of their pocket.
- You Don't Look Like You: None of the playable characters look like Doomguy all that much.
- No Name Given: In the game, though the novels call him John Kane. Quake Champions gives him the semi-canon moniker of Doom Marine, as opposed to Doom Guy for the original character and Doom Slayer for the reboot.
- The Stoic: He never shows any kind of emotion, except for shock upon seeing the Cyberdemon.
- Sole Survivor: By the end, he's the only surviving human.
- Weapon of Choice: In the majority of the game's cutscenes, he wields the shotgun.
- Anti-Hero: In addition to being more menacing looking, he didn't hesitate to power the artifact using dead humans he encountered throughout the base. Human or demon, he will not distinguish. However, his intentions are to stop the demonic invasion for good, even willing to perform a Heroic Sacrifice knowing that there is no turning back.
- Nice Job Breaking It, Hero!: The Engineer technically caused the second demon invasion of Mars by disturbing the Artifact. He makes amends by stopping it singlehandedly.
- Uncertain Doom: He enters Hell knowing it's a one-way trip, but after he defeats the Maledict, the screen fades to white, and the expansion ends with McNeil's voice saying "Marine...? Marine... Welcome home." It's left ambiguous whether he actually survived, or ended up in the afterlife.
The Bravo Marine
A UAC official sent in to investigate the shady activities of Doctor Betruger in Doom 3.
- Almost Dead Guy: When you finally manage to meet him face to face near the game's end, he is gravely wounded, but he lives long enough to give his PDA (and access) to the Marine.
- Big Good: Got called in to sort through Betruger's shenanigans and get the project's bottom line back on track. When things literally end up going to Hell, he spends most of the game trying to contain the crisis so it doesn't reach Earth, and aiding the marine in trying to figure out just what the hell is going on.
- Badass Bookworm: Despite being a bureaucrat-type, he manages to survive the demonic invasion, and even after his bodyguard's death, he manages to stay alive almost to the end of the game.
- Honest Corporate Executive: He's certainly a refreshing authority to have around given Betruger keeps putting lives in danger (while simultaneously creeping the shit out of all his employees rather than displaying leadership) and is more interested in his infernalist secret agenda than actually running the day to day operations he's supposed to be in charge of. Swann gets fed up with his bullshit pretty quickly.
- The Needs of the Many: Warns against sending a distress signal to the fleet, as this could potentially lead them into a demonic trap that could expose Earth to attack. He's 100% correct.
- Reasonable Authority Figure: Sent in because Betruger has gone off the deep end, and tries to solve it as best he can with the Marine's help.
A tough, imposing looking figure who serves as Swann's bodyguard.
- BFG: He's armed with one of the first functional models and uses it to fight the invasion. Gets stolen by Kelly / Sabaoth when he mortally wounds Campbell.
- Hero of Another Story: He manages to keep Swann and himself alive and well through most of the game. His mission through the Mars facility matches the Doom Marine's almost step for step, though he was always just ahead. He's one of the only other humans to be seen killing demons.
- Number Two: Being Swann's bodyguard, he naturally assumes this position.
- Sacrificial Lion: He gets killed by Sabaoth.
- The Worf Effect: He is mortally wounded and his BFG gets stolen by Sarge, to show how much of a threat Sarge is.
The Marine's superior officer in Doom 3.
- Ambiguous Situation: The game never clarifies if Kelly was on Betruger's side the entire time, or if he was converted into a demon later in the game. At the very least, it's implied that whether the signal for reinforcements was sent by the player or not, he was converted shortly thereafter and prior to reaching the Delta Labs as he attacks Campbell around that time and lures the player into an ambush.
- Bad Boss: He's verbally abusive and denigrating, even for a Drill Sergeant Nasty type character, and seems to be very impatient, often telling the player to "Pick up the pace!" (even while you're in the middle of fighting). He does drop the abuse and becomes much more professional after the shit hits the fan, though. Then he turns into a cyborg-demon-zombie and tries to kill you.
- BFG: He sports a BFG-9000 when you fight him as Sabaoth.
- He has a personal one in Resurrection of Evil, when you find a good old-fashioned Sawed-Off Shotgun in his office. Apparently he killed a bear on Earth with it.
- Body Horror: Is fused to a tank and various mechanical parts in the aforementioned fight as Sabaoth.
- Drill Sergeant Nasty: He has little patience for anyone who slacks off, as the player learns at the beginning.
- FaceHeel Turn: He gets subverted by the demons at some point after the invasion, and ultimately he becomes a cybernetic demon warrior named Sabaoth, whom you face as a boss-fight.
- Jerkass: See Drill Sergeant Nasty.
- Mission Control: Throughout the game, Sgt. Kelly contacts you over the radio, giving you orders and directions.
A UAC scientist who, having survived the demonic invasion of Doom 3, returns to oversee the operations in Resurrection of Evil.
- Heroic Sacrifice: Tells the Engineer to shut down the Mars base's life support so she has enough energy to power a teleporter to Hell, in order to ultimately destroy the Artifact.
- Mission Control: She replaces Sergeant Kelly.
- Morally Ambiguous Doctorate: Zigzagged. Despite her connection to the teleportation experiments, she's the one who blew the whistle on Betruger's activities prior to Doom 3, and attempts to stop the demonic incursion in Resurrection of Evil.
- Small Role, Big Impact: She does not appear at all in the first game (only her PDA can be found), but she's the reason Swann got called to Mars, and is partially responsible for Betruger's plan failing.
The UAC research director on Mars in Doom 3. The revolutionary teleportation experiments are his brainchild and personal project, but he's becoming increasingly unhinged, to the point it's raising concerns amongst the UAC.
- Ax-Crazy: His demeanour may not change all that much, but the fact that he thoroughly enjoys the carnage he helped unleash upon the UAC shows all too well how completely insane he is at heart.
- Big Bad: Of Doom 3 and Resurrection of Evil.
- Cold Ham: He never raises his voice, even as he's making grandiose threats of demonic annihilation.
- Deal with the Devil: It's revealed in The Lost Mission that the demons contacted him in his dreams, offering him unlimited power in exchange for Earth.
- Devil in Plain Sight: A nearly literal example as he's affiliated with demons, yet despite looking rather like Hannibal Lecter, having a name that's German for "Deceiver", and generally reeking of evil most of the other people don't seem to suspect anything.
- Evil Sorcerer: Betruger turns out to be an evil demon cultist, and wields powerful demonic magic throughout the game. He uses this magic to create Zombie Commandos.
- I Shall Taunt You: He periodically contacts the player to engage in Evil Gloating.
- Karma Houdini Warranty: At the end of the original game, it's seems that he's gotten away with his crimes, having been whisked away to Hell and transformed into a powerful demon. Resurrection of Evil finally allows you to kill him.
- Mad Scientist: Responsible for the teleportation experiments that brought the demons to Mars to begin with.
- Meaningful Name: "Betruger" is German for "Deceiver" or "Trickster", and also sounds a lot like "betrayer".
- Morally Ambiguous Doctorate: Firmly on the side of the demons.
- Obviously Evil: Has a shaved head, a raspy voice, an ashen complexion, and a clouded-over right eye. He totally seems trustworthy.
- One-Winged Angel: Becomes the Maledict near the end of the original game, and has to be fought in this demon-dragon form at the end of Resurrection of Evil.
- Red Right Hand: His clouded, eerie-looking right eye is a subtle warning that there's something wrong with this guy.
- The Unfought: The player never faces him head-on in the original game. Averted in Resurrection of Evil, where he's the Final Boss.
When Hell first breaks loose in Doom 3, the majority of the civilian population are quickly possessed by Demonic spirits and transformed into Zombies. Alone, they're very little threat, due to their lack of agility, but they have a nasty habit of popping up from behind corners.
- Chainsaw Good: A variant with a hunched back and a leather mask shows up in a few spots in the late game that carries one.
- The Dead Have Eyes: There are some zombies that are headless, yet they can still see you.
- Dead Weight: Fat zombies are a little stronger and do more melee damage than thin ones.
- Elite Zombie: In addition to the standard zombie, there are also some special types:
- The Flaming Zombie, also known as "Bernie", which is Exactly What It Says on the Tin. He has more health and shambles a little faster than normal zombies.
- The Fast Zombie, identified by his brownish-green clothing. He shambles slightly faster, but otherwise goes down just as easily as a regular zombie.
- The Chainsaw Zombie, which is the strongest zombie type in the game next to the Commando. He carries a Chainsaw and is very aggressive.
- Everything's Deader with Zombies: They're created by Demonic Possession and arguably Technically Living Zombies (the very first zombie we see is converted straight from a living victim, implying at least some of the others you fight subsequently went straight from alive to zombie without dying first). They have some capacity for tool use, but these basic zombies are slow and stupid.
- Facial Horror: Some zombies come with this, depending on model type; thin zombies can have their lower jaw ripped clean off, whilst fat ones can have their face peeled off, exposing naked skull amidst bloody meat.
- Glass Cannon: They can deal surprising damage (especially the fat ones) but their slow speed and lack of durability cause them to be minimal threats unless they sneak up on you.
- Glowing Eyelights of Undeath: Some zombies have glowing eyes, which can be seen easily in the dark.
- The Goomba: These are the most vanilla enemies you face in the game.
- Night of the Living Mooks: They're zombies. What else did you expect?
- Possessing a Dead Body: They are former humans, both alive and dead, that have been possessed by demonic ghostly skulls.
- Undead Barefooter: The fat zombies are barefooted.
- Underground Monkey: The standard zombies have a variety of models, including scientists, maintenance workers, clerks, and, rarely, marines. Each model has a different appearance, appearing either faceless, jawless, or even headless.
- Unique Enemy:
- In one instance early in the main game, you encounter a Morgue Zombie, which is capable of running. He's the only one of his type.
- There's exactly one Chainsaw Zombie in the game wearing a party hat (a reference to a PDA email about a party in the Delta Labs), encountered within Delta Labs.
- In Hell, there are some Boney Zombies that are encountered in one area. They have a slightly faster shamble than normal zombies, but they move slower than the Flaming Zombies.
- Zombie Gait: With a few exceptions, most shamble slowly towards you.
Stands for "Zombie Security", the basic security troops of Mars are also quickly turned to Hell by the demonic spirits. They avert their civilian counterpart's Zombie Gait and attack with whatever weapons they had while alive. Though armor style varies slightly (shotgun-wielders have open faced helmets), and weapon loadout varies from pistol to machine gun to shotgun, they're all equal in strength. They equate to the Zombie Troopers of the classic series.
- Adaptational Badass: Compared to their Zombieman counterparts in the classic games. Both are possessed humans carrying submachine guns and shotguns, but Z-Sec enemies can take cover, use basic squad maneuvers, and fire their SMGs on full auto, while Zombieman were limited to walking at you and taking the occasional potshot. Z-Sec armor also lets them take a few shots before dying, while Zombiemen were pitifully fragile.
- Everything's Deader with Zombies: They're a variant of the regular zombies above created from the former security guards serving security detail on Mars. Unlike their brethren, they display no cannibalistic traits and are fast agile, and smart enough to use projectile weapons and basic tactics.
- Eye Scream: Judging by what we see on one of the monitors, as well as the suspicious amount of blood of the machinegun variant's visor, when they were possessed, their eyeballs exploded.
- Faceless Mooks: The machine gun-wielding variety wears an enclosed helmet.
- Glowing Eyelights of Undeath: The pistol-wielding variety has these.
- It Can Think: Unlike the normal zombies, these guys can use guns, utilize cover, and cooperate with each other to kill you.
- Patrolling Mook: Minus alarms. They are often found patrolling areas, like they used to do when they were human. They aren't called "Zombie ''Security''" for nothing.
- Radio Voice: The sound of radio chatter in Aramaic indicates that a Z-Sec is nearby.
- Shield-Bearing Mook: The extremely rare Riot Trooper variant.
- Short-Range Shotgun: Averted: the shotgun-wielding variety has a narrow spread on his weapon, allowing him to shoot from far distances.
- Unique Enemy: Only four shield troopers appear in the base game.
- Zombie Gait: Averted: these zombies retain their full mobility from life.
Former elite UAC Marine troops corrupted by demonic energies and mutated into monsters that now serve as Betruger's personal warriors. Dramatically stronger, quicker and tougher than humans, they tend to fight with chainguns or a tentacle arm. They're analogous with the Chaingun Zombies from the original games.
- Close-Range Combatant: The tentacle Commandos have no ranged attack, relying on their tentacle and kick attacks.
- Combat Tentacles: Most Commandos sport a single long tentacle for their right arm, which they use to attack with.
- Elite Mooks: They are the strongest former human type enemy in the game.
- Everything's Deader with Zombies: They're a particularly different version of the Z-Secs above.
- Gatling Good: Later in the game, you encounter Commandos carrying chainguns.
- Made of Iron: Much, much tougher than the Z-Secs you've fought up until this point, even though they're barechested instead of wearing armor.
These demons are functionally imps on steroids, having a similar attack set.
- Authority Equals Asskicking: They're very high up in the demon hierarchy.
- Composite Character: They're a combination of the original games' Hell Knights and Barons of Hell, with the Baron's resilience.
- Eyeless Face: Played; while they do have eyes (they're in the fleshy parts on both sides of their mouths), they're tough to see, giving them this appearance anyway - perhaps as a contrast to the multi-eyed Imp.
- Informed Ability: An audio log indicates they move quite fast, though in gameplay, they aren't.
- King Mook: They stand head and shoulders above the other demons.
- The first 2 Hell Knights you fight, at the main Delta Labs portal to Hell, have more health than normal Hell Knights and are Doom 3's equivalent of the Barons of Hell fight from the end of Episode 1.
- Lightning Bruiser: In an audio log, the recorder specifically says that something that big should not be able to move that fast, though they move nowhere near as fast in the main game (though it's possible the recorder was referring to the Helltime Hunter, which is fought shortly after where the log is found).
- Made of Iron: They can take three direct hits with a BFG-9000 (or one level-3 BFG charge).
- Mighty Glacier: They don't move very fast, but hit hard, and can take a lot of damage.
- Took a Level in Badass: Intimidating as they are, by the time they show up in the base game, the player has acquired enough weapons and ammo to take them down without too much trouble, especially once they acquire the Soul Cube. Meanwhile, The Lost Mission has no Soul Cube and brings in the Hell Knights much earlier, when some of your ammo remains limited and before you've even acquired some of the tougher guns, making them far more dangerous.
- You Don't Look Like You: Looks practically nothing like their classic counterparts.
Fire-wielding demons that can also summon other demons.
- Enemy Summoner: Can spawn in many of the non-boss demons, ranging from Imps to Hell Knights.
- Playing with Fire: Can unleash a fast-moving column of fire, with some also able to make the ground erupt in flame underneath the player in a manner similar to Doom II (though the player can now avoid it by staying on the move).
Large floating demons that spit plasma.
- Airborne Mook: They float in the air.
- Breath Weapon: They spit slow-moving globes of ball lightning, which you can actually disperse with a well-aimed shot.
- Close-Range Combatant: In spite of their advantage, they still hover closer and closer to the Marine to bite him, occasionally taking a pot-shot with their Breath Weapon.
- Extra Eyes: Have two extra pairs of eyes.
- You Don't Look Like You: Basic body shape and mechanics aside, this Cacodemon is a dull-colored, six-eyed creature with webbed tentacles and a seemingly exposed brain, a far cry from the lumpy, bright red and one-eyed classic ones.
Disturbing enemies, consisting of babies with fly wings and claws.
- Deadly Lunge: They attack by jumping at you from a pretty long distance.
- Fragile Speedster: They're not very strong, but they move very quickly, especially when jumping, which makes it hard to hit them.
- Mini Mook: The smallest ground-based demon in the game.
- Mix-and-Match Critters: They have human baby bodies, fly wings, claws, and no legs.
A large quadrupedal demon with an eyeless face and cybernetic lower body.
- Body Horror: According to id Software, they're born with flesh covering their face, forcing them to eat their own face in order to survive.
- Close-Range Combatant: Possessing no ranged attacks, they simply charge at you.
- Cyborg: Their lower bodies are mechanical.
- Eyeless Face: They have no visible eyes.
- Lightning Bruiser: They're reasonably fast (even able to leap sideways to dodge projectiles if they have the space to do so) and quite tough, taking 3 full close range shotgun blasts to bring down. Their bite attack also does higher-than-average melee damage.
- You Don't Look Like You: For some reason they look completely different than the original version, being quadrupeds with no eyes or horns and having a cybernetic back half. The only similarity is they are both (mostly) pink.
Leathery creatures with multiple eyes that attack by throwing plasma balls.
- Deadly Lunge: They often surprise you by pouncing at you from unexpected areas.
- Demoted to Extra: They aren't absent in Resurrection of Evil, but the Vulgars take their place as the most common enemy, leaving them with only limited appearances.
- Extra Eyes: They have multiple eyes.
- The Goomba: They're one of the most common enemies in the game and the only enemy type that appears in every single level of the game (except the brief prologue level that features no enemies at all and Delta Labs Sector 4).
- Hoist by His Own Petard: In Resurrection of Evil, it's quite possible to catch their fireballs with the Grabber and kill them instantly with it, as demonstrated in a cutscene by a marine with said weapon.
- No Sneak Attacks: They're often kind enough to alert their presence to you by screeching first.
- Took a Level in Badass: They're more dangerous than the imps in the first two games. Instead of just throwing easily to dodge fireballs and scratch you if you get too close, their plasma balls are faster, gives more damage and they will lunge at you with incredible speed.
- Wall Crawling: They often show up by clambering out of vents, climbing up to balconies, crawling down walls or squeezing their way out of gaps in the walls.
- You Don't Look Like You: These imps are grey, scaly/leathery creatures with multiple sets of eyes.
Floating head demons propelled by rockets.
- Airborne Mook: They float around and attack by charging at you.
- Facial Horror: Pale, dead-eyed heads of women, mounted on a rocket engine with their jaws split open and their teeth seemingly mutated into razor-sharp fangs.
- Fragile Speedster: They move quite quickly, but go down with just two or three pistol/machine gun shots.
- You Don't Look Like You: Instead of the horned, flaming skulls we all know, these Lost Souls appear to be pale human faces with distended jaws and needle-like teeth mounted on a small rocket.
A two-headed demon with five legs.
- Close-Range Combatant: Possessing no ranged attacks, they simply charge at you and try to claw you.
- Fragile Speedster: Much faster than Imps, but weaker, even weaker than regular zombies(they take 4-5 pistol shots to kill, while regular zombies take 6-7).
- Multi-Armed and Dangerous: They have five limbs.
- Multiple Head Case: They also have two heads.
Giant demons with flamethrowers instead of arms.
- Animal Motifs: While not explicitly based on elephants, they have multiple physical features that make them resemble bipedal elephants. The "feeding tubes" attached to their faces along with the two larger face tentacles invoke the image of an elephant's trunk and tusks. Their feet are also shaped like an elephant's foot, not to mention their physical size (elephants are the largest land-based animals on Earth).
- Arm Cannon: Each arm has been replaced by a huge cannon, which they use to kill anything in their way.
- Cthulhumanoid: Their faces have tentacles that make them look a lot like Cthulhu.
- Dissonant Serenity: In contrast to all of the other monsters, as well as their own classic counterparts, the Mancubi are unsettlingly calm as they battle the player, with placid expressions in their eyes and almost never raising their voice above a low grumble.
- Fat Bastard: They certainly look the part as the largest and (by far) heaviest non-boss enemies with very flabby torsos.
- Mighty Glacier: They have the most health and are the physically largest of the non-boss enemies (they're shorter than a Hell Knight but have considerably more girth), and their flamethrowers deal a lot of damage, but they thankfully move slowly.
- Playing with Fire: Use flamethrowers.
Skeleton demons equipped with shoulder-mounted missile launchers.
- Dem Bones: As usual, they're walking missile-armed skeletons. A closer look reveals that they're seemingly covered in transparent jelly-like flesh.
- Elite Mooks: They're stronger than most demons.
- Homing Projectile: Their missiles.
- Scary Skeleton: Skeleton demons with missile launchers.
- Artificial Stupidity: They can't attack you if you're standing on a higher elevation, even if it's just a foot.
- Deadly Lunge: Attack by jumping at you.
- Unique Enemy: They're only encountered in Delta Labs in the original Doom 3 after returning from Hell, though they appear a couple more times in Resurrection of Evil.
- Zerg Rush: They attack in large groups.
Demons that resemble upside-down human heads with spider legs.
- Deadly Lunge: They attack by jumping at you.
- Demonic Spiders: Literally.
- Suicide Attack: They have the ability to explode if you are in a spot where they can't reach you.
- Zerg Rush: Like the Ticks, they attack in large groups.
A demon that can teleport.
- Blade Below the Shoulder: Organic variant, it doesn't have hands, only bone blades for forearms.
- Cyclops: Unlike the Imps, it seems to possess a single large eye embedded in a sponge-like cranium.
- Sinister Scythe: Has arms shaped kinda like scythes, which he uses to slash at you.
- Teleport Spam: They teleport every few seconds to mask their approach. While "out of phase", bullets pass through them, but they can't travel through walls, obstacles, or doors.
Floating skulls, only encountered in Resurrection of Evil and The Lost Mission. They replace the Lost Souls from the main game.
- The Goomba: So weak they can be grabbed and dispatched with the Grabber.
- Revisiting the Roots: Unlike the vanilla Doom 3's Lost Souls, the Forgotten Ones are meant to be closer to the original game's Lost Souls, as floating flaming skulls.
A grayish demon that appears only in Resurrection of Evil. They attack by throwing blue balls of plasma. These demons are unique in that they have a green teleportation effect.
- Chuck Cunningham Syndrome: The Lost Mission brings back the Bruisers and the Forgotten Ones, the other two new monsters from Resurrection, but the Vulgars are a no-show.
- Expy: They look kinda like a spidery, demonic Xenomorph.
- Hoist by His Own Petard: Just like the Imps, they're easily dispatched using the Grabber to give them back their own energy balls.
- Lightning Bruiser: They're fast and deal suprising damage despite their great numbers.
- Mooks: They take the imps' place as the main demonic fodder of the expansion pack. They act a lot like imps, but are slightly more dangerous, as their attack is slightly faster and they have a noticeably smaller hitbox making them more difficult to hit.
- Replacement Mooks: They replace the imps early on as your primary low-level demon.
- Xenomorph Xerox: Their postures, elongated craniums, and bladed tails give them this vibe.
A heavily augmented demon encountered in Doom 3: Resurrection of Evil and Doom 3: The Lost Mission. Sort of a hybrid of Hell Knight and Mancubus.
- Arm Cannon: Two flame cannons, like the Mancubus.
- Beam Spam: What makes him feel more dangerous than the Mancubus; his attacks do the same damage, but he launches volleys of them with far greater speed than the Mancubus.
- Boss in Mook's Clothing: Easily the toughest non-boss enemies in the game. Unless you have an Artifact charge to help take them out quickly, each one puts up a Hell of a fight, and you often fight 2 or 3 of them one after the other.
- Hollywood Cyborg: Cybernetic legs, guns for arms, and an electronic screen implanted into his face that displays snarling teeth.
- Lightning Bruiser: He's actually squishier than the Mancubus (825 health to their 1000 health), and less potent in melee (he barely does half the melee damage they do), but he moves — and shoots! — a hell of a lot quicker and can easily kill you if you're not careful. He can even quickly dodge sideways to evade projectiles, though he does this rarely.
- Playing with Fire: Hurls rapid-fire volleys of fireballs, like the Mancubus.
- Took a Level in Badass: Like the Hell Knights, their appearances in The Lost Mission are far more intimidating purely as a result of game design. The player is forced to battle them in a completely fair fight every time, since that campaign lacks Resurrection of Evil's time-slowing, ability-boosting Artifact item, making them far more difficult to take down.
- TV Head Robot: Their lower face consists of a television screen, which displays a different image depending on its alert state.
A large monstrosity with the body of a spider with a humanoid torso, similar to a centaur.
- Degraded Boss: Downplayed. After being defeated as the first boss, only two more show up as a mini-boss fight, and another in a similar fashion in The Lost Mission, though by that time they're not much more threatening than a Mancubus or Hell Knight.
- Early-Bird Boss: The most powerful weapon you'll have when you first encounter her is the plasma gun.
- Expy: Doom 3's version of the Spider Mastermind.
- Fan Disservice: The Making of Doom 3 book states she was built with the concept "Sexy + Gross = Creepy".
- Giant Space Flea from Nowhere: Unlike all the other bosses there is no forshadowing for her and she seemingly just appears at random. The second encounter inside the ruins inside the site is foreshadowed by the spiked balls they love to toss around.
- Mind over Matter: As ranged attack, Vagaries can telekinetically lift debris and spiked balls and send them fly against you.
- Monster Is a Mommy: Possibly. Earlier in the game the player hears "They took my baby" said by a voice similar to the Vagary's.
- Also, given that the Vagary's boss fight takes place at the end of the Alpha Labs, which is literally crawling with the other spider-based enemies, the Trites, there is a popular theory among the fandom that the Trites have established an insect-like colony within the Alpha Labs with the Vagary as their queen.
- If you can spare the time to look at the Vargary's abdomen when fighting her, you'll see it's translucent, with a giant demonic fetus floating inside! It actually looks somewhat similar to the Mancubus.
- Spider People: Of the spider-centaur variety. Also has spider-like eyes on their face.
Guardian of Hell
A massive blind beast that chases the player through the bowels of Hell.
- Attack Its Weak Point: The Soul Cube even tells you to. It helps that's essentially a big, glowing ball of teal light in the otherwise dark room.
- The Cameo: In Resurrection of Evil you can find some martian slabs depicting the Guardian's head.
- Cores-and-Turrets Boss: Half of one; it uses orbiting "Seekers" to compensate for its blindness.
- Everything's Better with Dinosaurs: Unlike the other generally-humanoid demons, the Guardian resembles a huge horned crocodilian beast and according to the creators they wanted to imply that he was some sort of ancient, dinosaur-like proto-demon beast.
- MacGuffin Guardian: The instant you approach the Soul Cube he manifests from a portal in the ground and proceeds to chase you.
- Mighty Glacier: Massive and heavy, bullets won't make him budge, but since he's blind he will slowly move across the arena, increasing its pace to a charge if you're spotted by his seekers.
- No-Sell: Thanks to his hard skin, he shrugs off all weapons unless hit in the "energy sphere" he uses to summon more Seekers.
- Spikes of Villainy: His hands are, essentially, organic morningstars.
The possessed form of Sgt. Kelly. Most of his body has been replaced with military hardware.
- BFG: Stolen from Campbell. He uses it against you when you fight him.
- Braggart Boss: He loves to trash-talk you as he fights.
- Creepily Long Arms: One of his remaining limbs is incredibly long and distorted.
- Ninja Pirate Zombie Robot: He has a mutant torso with tank treads for mobility.
- Ring-Out Boss: In an inverted variation, most of the arena is surrounded by a large gap... but when he treads over it, panels appear to support his weight, changing the morphology of the room. If you're not careful where you're standing, after Sabaoth is defeated the panels can slide back and send you plummeting to your doom.
- Tank Goodness: The lower half of his body.
The final boss of Doom 3. Even bigger than before.
- An Arm and a Leg: He's finished off when the Cube hacks his left leg before sinking itself inside its forehead.
- Arm Cannon: His right arm has been replaced with a missile launcher.
- Contractual Boss Immunity: To everything but the Soul Cube.
- Flunky Boss: He's escorted by a lot of minor demons for you to recharge your Soul Cube with.
- Gate Guardian: Apparently left behind by Betruger to watch over the Portal to Hell and slay all those who managed to venture forth this far.
- Giant Foot of Stomping: His melee attack, which is a One-Hit Kill. Hilariously, he can also kill imps and maggots by simply walking into them.
- Large and in Charge: The largest humanoid demon and the one guarding the portal to Hell.
- World's Best Warrior: The Soul Cube refers to him as Hell's mightiest warrior.
A trio of elite demons sent to retrieve The Artifact and spearhead the second invasion of the Mars base in Resurrection of Evil. The team consists of the Helltime Hunter, Berserk Hunter, and Invulnerability Hunter, which you fight in that order.
- Attack Its Weak Point: The Berserk Hunter. Shoot its "heart".
- Boss Arena Idiocy: The Helltime Hunter manifests from a portal which happens to have two turret-things on the sides shooting out shots of green plasma you can grab and fling at him.
- Burning with Anger: The Berserk Hunter.
- Flash Step: The Helltime Hunter. Thankfully, the fact that he turns into a massive globe of fire when he moves allows you to follow his movements and move out accordingly.
- Fog Feet: The Helltime Hunter has a mass of fire instead of proper legs, and overs above the ground.
- Shielded Core Boss: The Invulnerability Hunter uses four nearby power couplings to recharge his energy shield.
- Shockwave Stomp: One of the Invulnerability Hunter's attacks.
- Tennis Boss: The Helltime Hunter.
- Underground Monkey: All three Hunters are, essentially, reworked and souped-up Hell Knights, though possibly because they were Hell Knights empowered by Betruger.
- Victor Gains Loser's Powers: After death, their powers are absorbed into the Artifact for the player to use against the next one.
- Warmup Boss: The Helltime Hunter exists mostly to teach the player how to use the Grabber.
The new leader of Hell, fought at the end of Doom 3: Resurrection of Evil. A giant dragon-like demon that spews fire and summons meteor showers.
- Be Careful What You Wish For: In the final cutscene, he demands that the marine gives him the Artifact. The marine complies, alright... by shoving the Artifact down the Maledict's throat, killing him almost instantly.
- Big Bad: Of Doom 3 and Resurrection of Evil.
- Difficulty by Region: In the BFG Edition instead of summoning Forgotten Ones he just shoots more fireballs at you, which is much easier to evade.
- Draco Lich: He looks quite a lot like an undead dragon.
- Contractual Boss Immunity: Inverted; his attacks cut through your invulnerability if you try to use the Artifact.
- Final Boss, New Dimension: Naturally, facing off against the Maledict is done in a particularly isolated part of Hell.
- Flunky Boss: He likes to summon a lot of Forgotten Ones.
- Heads I Win, Tails You Lose: After his health is depleted, the fight immediately switches to a cutscene where he knocks the player character on his ass.
- Nested Mouths: The grotesque "head has a smaller head in its mouth" variant. Inside the skeletal, draconic head of the Maledict is the ranting face of Malcolm Betruger.
- Shows Damage: His wings get more tattered as you cut through his health, serving as a visual indicator for how much damage you've dealt to him.
- Skull for a Head: His head resembles a blackened skull.
- Was Once a Man: He was originally Malcolm Betruger.