Doom/Complete list of enemies

The following are enemies in Doom, , Doom II: Hell on Earth and Final Doom. Most of these enemies also make appearances in Doom 64 and Doom RPG. Most of the enemies in the games are Demons from Hell; otherwise they are possessed, undead humans. Many of these creatures have become iconic in computer gaming. In the Doom novels written by Daffydd Ab Hugh and Brad Linaweaver, the creatures are initially thought to be demons, but are later revealed to be an alien race bent on the conquest of Earth. (Although this is only in the novels, and as such is not canon.)

Zombies
Zombies are undead soldiers who have been turned into brain-dead killing machines by the demons. They are the only non-demonic enemies in the game as well as the only ones who drop ammunition (half the ammo of a fresh clip or a weapon pick-up) when killed (the dropped ammunition, however, can be lost if a door or crushing ceiling comes down on it). Owing to their usage of bullet weapons, zombies can be easily tricked into engaging in monster infighting with other creatures as well as their own kind.

Former humans and sergeants will close the distance on their foe, and then circle, pausing every few steps to fire a shot. Commandos, however, once within line of sight of their foe, will continuously fire their chaingun, only rotating to adjust to their target's movements. Moving out of their line of sight, such as hiding behind a wall or using a lift, will break their lock and cease their firing, and they will be on the move to seek out their foe; however for each 2 shots fired there is chance of about 15% that chaingunner will continue firing.

Three different forms of zombies are featured in the Doom games:
 * Former human / Zombieman: 20 HP, wears beige armor and has a green crewcut - wields a rifle, fires single shot that deals from 3 to 15 damage. Drops an ammo clip when killed. Appears in Doom, Doom II, Doom 64 and Final Doom.
 * Former sergeant / Shotgunner: 30 HP, wears black armor with bald head. Fires 3 pellets from his shotgun that drops on death, with each pellet dealing 3 to 15 damage. Appears in Doom, Doom II, Doom 64 and Final Doom.
 * Former commando / Chaingunner: 70 HP, dark red armor - wields a chaingun that he drops when killed. Fires 8 shots per second with each shot dealing 3 to 15 damage. Appears in Doom II, Final Doom and the PlayStation and Sega Saturn versions of Doom.

In the Doom novels, zombies are found in various forms, ranging from former civilians to soldiers. However the former commandos depicted there (referred to as Clyde) are not zombiefied humans, rather they are either genetically engineered human copies or human traitors who have been genetically altered to look alike. They also emit a "sour lemon smell" when killed or nearby.

In Doom 64 there are no real changes in behavioral patterns amongst the zombies; they simply walk and shoot. The only real physical difference is that the Sergeant's pants are a slightly darker shade than the Former Humans (which makes them harder to discern within Doom 64's darkness). The Former Commando does not appear in Doom 64.

In the Doom RPG two classes of zombies exist, each with three variants corresponding to their difficulties. The Zombie classes are named: Zombie Private, Zombie Lieutenant and Zombie Captain. Commando classes are named: Troop, Commando and Assassin.

Imp
The Imp is the basic demonic enemy and common in all of the games because they appear in almost every level, where they appear with a relatively humanoid appearance. In the original games, Imps have brown skin, red eyes, and spikes on their shoulders, elbows and knees. They usually emit a hissing sound when alerted and have 60 HP. They attack at long distance by firing fireballs from their hands, and up close by scratching with sharp claws with both attacks dealing 2-24 damage.

In the Doom novels, imps appear as they do in the older games - however, some can talk, as they are made "leaders" of small groups. Their fireball attack is produced by spitting in their hand, where the mucus then turns into fire. They are referred to as "spinies" and "imps".

In Doom 64, there are the common Imps, which act like their counterparts, though their appearances are slightly different; they have the same physical build and colour, but seem to be devoid of a mouth and several of the protruding spikes. There are also the Nightmare Imps, which have a transparent purple/blue appearance to them, move faster, and fire purple fireballs that also fly faster, though they look essentially the same.

In Doom RPG, three variants of Imp exist. They are Impling, Imp, and Imp Lord. They are weak against shotgun shells.

Demon
The Demon (also known as Pinky Demon, Bull Demon) is a well-known monster found in all incarnations of the series. In the original series, the Demon has a hunched back with pink skin, clawed feet on its hind legs, a large head with sharp teeth pointing out, two large muscular arms, beady gold eyes, and two bull horns on the head. Its only gait is a run. Its only attack is a close range biting attack, but because of their brute strength and tendency to appear in packs, they can be very deadly, especially in open areas where they can quickly surround the player. In regular difficulty, the use of the chainsaw will usually allow the player to stun and kill an individual Demon without harm; however this does not work if a game parameter is set to Fast Monsters, such as in Nightmare Mode. They have 150 HP, and emit a loud snarl when killed (also producing a noticeable thud upon falling to the ground).

In the Doom novels, the Pinkys appear unchanged, albeit found in various sizes. Characters refer to them either as "Pinkies" or "Demon".

In Doom 64 the Demon is referred to as the "Bull Demon". Their main functions remain the same, though their physical look is changed rather drastically; it looks much more demonic, its head not as big, and it has larger claws on its hands. There are also Nightmare Demons, which have the endurance of a Baron of Hell, and is much faster, somewhat transparent and have a shade of green for their color.

In Doom RPG, in addition to Bull Demon and Pinky, the latter variant stronger than the former, there is also the Belphegor variant, which is stronger than either the Pinky or the Bull Demon. In Doom RPG, they are resistant to Rockets.

Specter
Specters have been featured in the Doom series since the release of the first game. These creatures are identical to Demons in terms of form, sounds and type of attacks, however they can be distinguished by their permanent partial invisibility feature, to which they likely owe their name. Though they feature a normal blood-splatter when injured, these monsters retain their invisibility after death, and a crushing ceiling will leave a pile of invisible blood.

Specters do not have sprites of their own; the Demon's sprite must be edited to change them.

In Doom and Doom II, partial invisibility causes Spectres to appear as "shimmering", nearly translucent beings, making them hard to spot in darker areas or against certain textures (such as grey speckled walls). However, in bright areas, they are noticeably visible and "spotty".

In the PlayStation version of Doom, Specters do not "shimmer", rather they are rendered as faded and semi-transparent. PlayStation Doom also includes the so-called "Nightmare Spectres", a tougher variant of these creatures which look like walking shadows. They are roughly twice as strong as their Pinky cousins.

They appear in the Doom novels with no difference to their game versions. They are referred to as "ghosts" and "specters".

In Doom 64 the Specter does not shimmer, but is almost completely invisible in the game's dark atmosphere. They disappear upon finding you and, when killed, shift into an opaque dark green color.

The Specter is absent in Doom RPG.

Lost Soul
Lost Souls in Doom and Doom II are portrayed as floating horned skulls with flames coming out the back of their heads. They have 100 HP (reduced to around 50HP in the PlayStation release) and their attack consists in charging forward in an attempt to ram their intended target. A direct hit from a weapon on a charging Lost Soul will force the creature from the direction of the hit, halting its attack and rendering him harmless until he hits a solid object. Also, the speed and distance in which a Lost Soul in knocked back from is determined by the force of current weapon used. Upon death, Lost Souls will explode in a cloud of flame and smoke, leaving behind no corpse. Owing to their attack type these demons are particularly susceptible to cause monster infighting between their own similars or against other creatures, especially when they appear in large groups. In Doom II, Lost Souls can also be spawned by Pain Elementals.

In the Doom novels, Lost Souls are flying machines, with the same appearance as in the game, but flying on rocket fuel and exploding in a rain of mechanical parts when destroyed. Characters name them "flying skulls".

In Doom 64 the Lost Souls appear translucent. When attacking, they fly at you much faster than in the PC version and with much more impunity. They tend to hunt in packs as opposed to solo.

In the Doom RPG, Lost Souls exist as a class and as a monster. The other creatures in the class are known as Phantom and Nightmare. They are weak against Fire Extinguisher Blasts.

Cacodemon
Cacodemons are large red spherelike demons, with horns, one green eye, and a large mouth that can spit ball lightning and bite. The Cacodemon graphic first appeared in the code of an alpha version of Doom, released on May 22, 1993; it first appeared as a live adversary in a press release version of Doom released on October 4, 1993. In the finished game, played at the default skill level, the Cacodemon first appears in the first level of the second episode of Doom, "Shores of Hell". Cacodemons appear in almost every level in the second and third episodes. It has 400 HP.

The original Cacodemon's design may have been inspired by the beholder and the astral dreadnought from Dungeons & Dragons. The artwork is alleged to be a replication of an illustration of an astral dreadnought from the Dungeons & Dragons Manual of the Planes. The history of the Cacodemon has also attracted much attention in the Doom community. In fact, a few plush Cacodemons exist. One known as Hissy, created by a member known as Chrozoron, has been sent on a world tour to several Doom players, and is a cult icon in their community. Another, more accurate, plush representation known as Pixel was made in late 2004 by Hughe as a challenge from a friend. More information about the plush cacodemons can be found on the Doom Wiki.

In Doom 64, the remade Cacodemons are brown in colour, their single eye reminiscent of a cat's eye, and they have two arms, with chains at the wrists. Their ball lightning flies out faster and they emit a much more fiendish "hissing" sound when they spot you. There are also "Nightmare Cacodemons," which are almost completely transparent, can shoot three fireballs at a time, move much faster, and have more HP.

Doom RPG, in addition to the Cacodemon, features the Malwrath and Wretched monsters. Malwraths are weaker versions of the Cacodemon while Wretcheds are stronger.

Cacodemons are identical to the game counterparts in the Doom novels. They also have a strong hatred of Barons of Hell, as both races will actively kill each other over humans. There is also evidence on the secret level in the episode The Shores of Hell, in which the player sees both dead bodies of Cacodemons and two Barons of Hell chained up in another room. They are named "pumpkin" by the characters due to their appearance, and the smell when killed.

Pain Elemental
Pain Elementals are introduced in Doom II. They are similar in appearance to Cacodemons, except that they are brown in coloration, have two small horns, and stubby short arms. They do not appear in Doom 3 or Resurrection of Evil. Just like the Cacodemon, the Pain Elemental has 400 HP.

Pain Elementals do not attack their targets directly; they spit out Lost Souls to attack the target. The longer it takes to destroy the demon, the more Lost Souls will be summoned. However, if there are more than twenty Lost Souls in the level, no more will be spawned until some are killed, potentially making the Pain Elemental harmless. An infamous scene in the Doom custom level pack "Hell Revealed" had several Pain Elementals rendered harmless by the limit (20 Lost souls were hidden in a room outside the normal level). When the player picked up a Megasphere, the hidden Lost Souls would be crushed and the Pain Elementals would attack. When killed, the Pain Elemental explodes, spawning three Lost Souls, unless restricted by the twenty Lost Soul limit (the Doom II manual cautions "killing him is almost as bad as letting him live").

The Doom games that contain Pain Elementals (including the PlayStation version of Doom) contain a glitch that sometimes occurs: when a Pain Elemental is destroyed near a wall, it may spawn one or two Lost Souls inside the wall. These Lost Souls are trapped, and cannot attack targets, only follow the wall back and forth. Pain Elementals can engage in monster infighting if they are injured by other monsters. However, since the Lost Souls they spawn are separate monsters, any enemies they hit will attack the Lost Soul that hit them; monsters will never directly engage a Pain Elemental.

In Doom 64, the remade Pain Elementals have two mouths instead of one (giving them twice the Lost Soul birthing power), where the arms used to be. They also have a small tail and long black hair on the back. When they die, they only shoot out two Souls instead of three.

In Doom RPG, they are variants called Beholder and Rahovart. Both are weaker than the Pain Elemental.

Pain Elementals are unchanged in the Doom novels, though only one appears, in the third book. Characters call it a "super pumpkin".

In early pre-release publicity screen shots of Doom II the Pain Elemental was shown launching fireballs, in the manner of a Cacodemon, and also infighting other monsters. 

Mancubus
The Mancubus (collectively referred to as Mancubi) is a fat, cybernetic humanoid demon which was introduced in Doom II. They have fireball launchers bolted directly onto both arms, and fuel tanks for the weapons mounted on their backs. They have 600 HP. They move slowly but it is more difficult to avoid their attacks of multiple, spread-out fireballs than the singular fireball attacks of some other enemies. They are reasonably common in Doom II, with their first appearance in the seventh level. The Doom II manual remarks that their only positive trait is that they are "a nice wide target". The size of their fireballs is also a double-edged sword, it makes it easier for them to hit the player but also inadvertently other monsters; the large size of the projectiles makes it difficult for them to squeeze through cracks. The Mancubus' fireballs occasionally pass through walls, apparently a glitch.

In the Doom novels, their appearance and function is relatively the same, though they have poor eyesight and hearing due to tiny eyes and ear openings, combined with massive rolls of flesh and fat. It is called "fatty" by the characters.

In Doom 64, the Mancubus is virtually unchanged save for subtle changes in physical appearance. However, they walk in a much more different fashion (they wobble side to side when walking.) Their fireballs are smaller and a bit easier to avoid, but they fly faster and possess limited homing capabilities.

In Doom RPG, the Behemoth and Druj monsters are variants of the Mancubus. The Mancubus is stronger than the Behemoth but weaker than the Druj.

Baron of Hell
Barons of Hell resemble the classical 'goat-legged' depiction of Satan, also being similar looking to minotaurs. They attack the player by scratching with their claws when close or throwing fast-traveling green balls of plasma at a distance.

A pair of Barons, referred to internally by id Software as the "Bruiser Brothers" (a reference to the Hammer Brothers from the Mario series), serve as the bosses at the end of Knee-Deep in the Dead, the first episode of Doom. Barons also appear as regular enemies in the later episodes and in the sequels to the game. Before the introduction of Doom II enemies, Barons were often considered by some to be sub-bosses.

They are described in the Doom manual as "tough as a dump truck and nearly as big, these Goliaths are the worst things on two legs since Tyrannosaurus rex"; the Doom II manual later described them as follows: "The Hell Knight was bad news but this is Big Daddy. These bruisers are a lot like the Knights, but look somewhat different and are twice as tough to kill. Keep your eyes open". The original Baron of Hell description was given to the Hell Knight in the Doom II manual instead.

The Baron of Hell artwork first appeared in the Doom 0.2 alpha version

Barons are the third strongest of all creatures in Doom, with 1000 hit points. Despite their remarkable endurance, Barons of Hell often pose a relatively lesser threat compared to some of the weaker, more maneuverable, and more numerous monsters. This is attributed to the fact that their projectiles can easily be dodged if given sufficient space, especially by circlestrafing. As a result of their high stamina but low speed, the Baron of Hell was a rather unbalanced monster and it was infamously known for forcing the player to waste lots of ammunition to defeat, so they essentially serve as meat shields for weaker monsters with stronger attacks. Barons are particularly dangerous in tight corners and mazes, due to the fast speed of their projectiles and deadly close combat capability, while their endurance enables them to prevail in attrition.

It should be noted that the Baron of Hell's first appearance in Doom was replaced with the Hell Knight in a similarly thematic cutscene in Doom 3. Also, in "Doom 3" the cutscene shows two Hell Knights coming out of the portal to Hell, which is very similar to the Bruiser Brothers' appearance.

In the Doom novels, they are nearly identical, but wear mechanical "wrist launchers" to fire their green plasma balls. They are called "hell princes" and "minotaurs" by the characters.

In Doom 64, the Barons are just about unchanged, though their appearance is warped to suit the game's different graphical appearance. They also throw distinct red fireballs, as opposed to the Hell Knight's green ones, and will engage in in-fighting with a Hell Knight as opposed to the PC games.

In Doom RPG, Baron is stronger than Hell Knight and Ogre, the other two enemies from same class.

Hell Knight
Hell Knights were introduced in Doom II with the primary intent of adding more balance to the game, after complaints that the similar Barons of Hell were too tough in terms of health, but not in terms of threat to the player, acting essentially as "meat shields"; with their lowered toughness, these creatures can be used more frequently in the game. Hell Knights appear and act like Barons of Hell, although Knights have half the hit points (500), a different tanned color and also emit different sounds. Like Barons, Knights' long range attack consists of launching greenish fireballs, while at close range they will try to scratch a target with their claws. Hell Knights are relatively difficult to cause to participate in monster infighting (compared to other Doom monsters) with each other or Barons, however they will react against all the other creatures if fired upon (in the PlayStation release, Hell Knights and Barons can and will fight each other if provoked, though it is not as easy as causing infighting with other enemies due to them not being encountered together often).

In the Doom II manual, the Hell Knight receives the description previously reserved for the Baron of Hell, which compares it to a "dump truck" in terms of size and strength. Owing to their similar appearance the manual also dubbed the Baron "big daddy" to the Knights.

In Doom 64 the Hell Knights remained virtually unchanged in general appearance, attack, and color. However, they are susceptible to in-fighting with several different demons, particularly Barons of Hell (the PC games do not have such in-fighting).

Hell Knights do not appear in the Doom novels, but are featured in the Doom RPG as part of the Baron class.

Revenant
Revenants are a class of demonic creatures introduced in Doom II. The Doom II manual states that they are previously dead demons resurrected by technology. They have 300 HP and resemble tall humanoid skeletons, characterized by hollow eye sockets and armor on their upper body which integrates two small shoulder mounted rocket launchers. They run relatively fast.

At close range Revenants will attack by punching their target (similar to the player's Berserk punch), while their long range attack consists in firing rockets, some of which can home in on their intended target. These weapons only cause half the direct damage of normal rockets (such as those used by Cyberdemons or the player), have no splash damage and are usually slow enough for experienced players to dodge or use to start monster infighting. Revenant rockets do have significant endurance due to their semi-tracking nature; occasionally such a projectile will follow the player through repeated turns, and it is possible for a player to have the rockets flying indefinitely by either running in circles or simply causing the rockets to orbit the player.

In the Doom novels, their appearance and function is unchanged and are described as having a thin skin over their bones. The coloring over their bodies are said to be normal clothes (when in the games, it's visceral gore). Characters in the novels theorize that the Revenants were poor attempts to genetically engineer human clones. The characters call them "bony".

Revenants do not appear in Doom 64.

In the Doom RPG, the weaker forms of the Revenant are called Ghoul and Fiend.

Arch-Vile
Arch-Viles are lean humanoid demons. They first appeared in Doom II, but also appear in Final Doom, and Doom 3. It does not appear in the original version of Doom. It was not included in the PlayStation version combining both games, due to the additional memory requirements necessary to load the large number of animation frames of the Arch-Vile.

They have the fourth-highest number of HP (700). Their only attack consists of blasting their enemies. It first raises its arms up, which causes non-damaging fire to raise around the targeted foe. The Arch-Vile then hunches over and clamps its hands together, releasing a blast which causes the target considerable damage, with some splash damage, and can send it flying into the air. This attack will always hit the target instantly, so long as there is a line of sight between the Arch-Vile and the target when the attack is finished. The attack can be avoided by either hiding behind an obstacle before the attack is finished, or by causing the Arch-Vile to flinch by damaging it, though it is very resistant to pain. The Arch-Vile will use this attack to engage in monster infighting with other monsters who accidentally hit it. In addition, the Arch-Vile has a special flag enabled that disallows infighting by other enemies; it is allowed to attack its fellow monsters, but they're not able to return fire or fight back. This behavior can be overridden in ZDoom, however, if the AV is summoned using the "Summonfriend" command, or if the Thing_Hate special instructs another monster to target the AV specifically.

In Doom II and Final Doom, Arch-Viles are the fastest monsters, and encountering two of them at once can be quite challenging to some players (often requiring use of the BFG 9000). The Arch-Vile also has the unique ability to resurrect other monsters. They can revive all monsters except Cyberdemons, Spider Masterminds, Lost Souls and Pain Elementals (since they leave no body), and other Arch-Viles. This power makes the Arch-Vile a priority to kill in battle, so that they do not keep reviving monsters and forcing the player to waste precious ammo. On occasion, in user-made maps, Arch-Viles may be hidden within pillars or inside secret areas where they are close enough to revive monsters but are otherwise difficult to reach themselves. Arch-Viles are also common in the Plutonia Experiment level pack of Final Doom, with one level being a labyrinth filled with Arch-Viles, and the player only gets a super shotgun for a weapon, plus there are no health packs along the way.

Its unique abilities are exploitable and can cause some bugs. Killing a resurrected monster will count towards the "Kill" percentage at the end of a level, making it possible to get more than 100% kills. It can be used to obtain some extra ammo, although it is somewhat risky. If there are a few zombies in the area, the Arch-Vile may revive them, and every time they are killed again, they will drop ammunition. Its fire attack can be exploited to do an Arch-Vile Jump and bypass some elements of a level and reduce game time. If an Arch-Vile resurrects a monster that was crushed to death, it can produce a ghost monster which is only vulnerable to splash damage from a rocket or barrel explosion and can move through some walls. However, this glitch has been fixed in several source ports for Doom. There is also a bug whereby if a game is saved while the Arch-Vile is in the process of using its fire attack, the game will crash when attempting to load the savegame.

An Arch-Vile makes an appearance in the second Doom novel, Hell on Earth, its nature simplified somewhat. It now merely contracts its body and "explodes" like a living bomb, an explosion it can survive. It is able to generate intense heat, enough to melt bullets shot at it. It cannot set others on fire and it is never shown to resurrect monsters. The main characters name it a "fire-eater".

Arch-Viles do not appear in Doom 64 or the PlayStation version of Doom.

In Doom RPG, the weaker form of Arch-Vile is called Infernis. The stronger form is called Apollyon.

Arachnotron
The Arachnotron is a partly mechanical, partly organic creature, loosely resembling a robotic spider, that was introduced in Doom II.

The Arachnotron appears to be a much smaller version of the larger Spider Mastermind and as such it bears much of the same form of its counterpart, including the large brain with two eyes and the metal platform with four mechanical legs attached. (Indeed, the Doom II manual goes so far as to refer to the Spider Mastermind as "mom" to these beings.) However, the Arachnotron lacks the shark-like teeth and evil grin of the Mastermind and, rather than red, it has blue eyes that shine red when the creature fires its weapon.

The Arachnotrons' metal platform has a plasma rifle attached, instead of the Mastermind's chaingun, a particular trait that makes these creatures deadly, as they rapidly unleash a stream of fast-flying greenish plasma with similar potency to the player's own plasma rifle. Despite the potency of the Arachnotrons' plasma rifles, it is relatively easy to avoid their fire, as they cannot lead their target with their plasma. Circle-strafing around an Arachnotron will render the monster unable to hit the player, allowing him/her to attack with impunity or even cause them to inadvertently target other monsters. Like the Mastermind, once they get a targeting lock, the Arachnotrons will stand still and continuously firing their weapons, only rotating to adjust to their target's movements. Moving out of their line of sight, such as hiding behind a wall or using a lift, will break their lock and cease their firing, and they will be on the move to seek out their foe.

Nearby Arachnotrons can be used by players to shield from their firing, as these creatures are not subject to monster infighting with each other. Owing to their impressive firepower Arachnotrons will defeat most enemies when engaged in monster infighting, but Barons of Hell, Spider Masterminds and Cyberdemons will usually prevail thanks to their larger amount of hitpoints when compared to the 500 HP of the Arachnotrons. Arachnotrons are quite sensitive to pain and have a 50/50 chance of flinching when hit by an attack.

Arachnotrons do not appear firsthand in the Doom novels, but are mentioned by soldiers on Earth who called them "spiderbabies." The presence of one is implied, though not confirmed in the second book. One is also mentioned in the prologue of the third book, Infernal Sky, as having killed the husband of a woman in hiding.

In Doom 64 the Arachnotron is much bigger than from the previous titles. They also possess two side-by-side plasma guns as opposed to one, and when attacking, fire out six semi-automatic twin bursts instead of a single continuous stream. They also have six legs instead of four. The bursts fly out faster, but are also a bit easier to avoid and strafe through. Their sensitivity to pain has also been increased, more so than the previous form.

Cyberdemon
The Cyberdemons resemble large, 10+ foot tall brown-skinned minotaurs, somewhat resembling the weaker Baron of Hell, with several unnatural cyborg enhancements, including a mostly metallic right leg, a prosthetic rocket launcher for a left forearm, wires lining down their midsections, and wires protruding from the right shoulder areas. The Cyberdemon is also the final boss in Doom III.

A Cyberdemon is featured on the box art and the title screen of Doom II. Cyberdemons attack the player by using their arm-mounted rocket launcher with rockets identical to those fired by the player, which are shot in threes, one at a time, per attack. The rockets also have splash damage, allowing them to damage targets with missed, but close, detonations. The Cyberdemon is the most powerful enemy in the series, and is infamous for its extreme difficulty. The Cyberdemon's attack is extremely powerful (even on the lower difficulty settings), if you have acquired 200% health and armor from previous levels, one rocket will bring your health down to 122%, and (if there is a break between hits), a second rocket will bring it down to 33%.

The Cyberdemon was originally designed as the end-of-chapter boss of the second episode of the original Doom, in level 8: "Tower of Babel", where the creature is awaiting the player in the courtyard section of the level, flanked by Lost Souls (on higher difficulties). It only makes one additional appearance in the original Doom in the secret level of the third episode, but several Cyberdemons appear in the sequels, Doom II, The Ultimate Doom, and Final Doom. Final Doom ' s secret level "Go 2 It" contains thirteen Cyberdemons, regardless of what skill level choice the player makes. In Doom II, the Cyberdemon makes its first appearance in the level "Tricks and Traps".

The manual for the SNES port of Doom lists them as "Half unfeeling machine, half raging horned devil. This walking nightmare has a rocket launcher for an arm and will definitely [sic] reach out and touch you. Make sure you're loaded for bear before you get to this guy." The Doom II manual lists them as "A missile-launching skyscraper with goat legs. 'Nuff said."

In the Doom novels, they are said to be five meters tall, and are half organic, half machine, with a rocket supply in the back and JP-9 rocket propellant as fuel. Their programming was pirated from an ore crusher design the aliens had found. The main characters name them "steam demons".

In Doom RPG, the Cyberdemon was created by the main antagonist, Kronos, during his visit to Hell.

In Doom 64, Cyberdemons are somewhat rare to find, only found in 2 regular levels ("Watch Your Step" and "No Escape"), not including the three hidden stages ("Cat and Mouse", "Hardcore", and "Playground", where you fight a Cyberdemon to end each stage). Physically, they are somewhat taller and slightly lankier than their previous forms, and appear much more fiendish and demonic in scope. They walk somewhat slower than the original creations, but this is off-set by the fact that their rockets fly faster. Their rocket launchers appear larger, but attack in the same three-shot attack as seen in the original titles.

In Wolfenstien RPG for the mobile phone, a completely organic Cyberdemon, here called the "Harbinger of Doom", appears as the final boss, summoned to our world by the nazis. It is completely immune to all normal weapons, and can only be harmed using the Spear of Destiny, which is given to the player after automatically retreating from the first confrontation with the beast. Interestingly, upon being defeated, the Cyberdemon's hand and foot, which are robotic in other appearances, are cut off, and he vows to return for revenge against the future generation. Thus it is implied that this is how the Cyberdemon originally received the injuries that required it to become a cyborg in the first place. Cyberdemons are also found in the roguelike game ZAngband and many derivatives, such as Gumband, Hengband, and ToME. There they have similar characteristics to Cyberdemons in the Doom series, although they have been given a tremendously strong close-combat attack in addition to their traditional rockets. The unique monster Oremorj (J. Romero backwards), the Cyberdemon Lord, can be found in Zangband and Hengband.

Spider Mastermind
The Spider Mastermind or Spiderdemon is one of the boss enemies in Doom, appearing in the last level of both the third and the fourth episode; it is also the second toughest creature in the series, owing to its 3000 HP which places it right after the Cyberdemon. The Mastermind can be described as a large brain with two red eyes and a mouth filled with sharp teeth, attached to a metal platform with four mechanical legs which also serves as housing for a powerful super-chaingun. The Arachnotrons in Doom II and Final Doom appear as a smaller version of the Spider Mastermind, and are implied by the Doom II manual to be its offspring.

Once they get a targeting lock, the Mastermind will stand still and continuously fire their chaingun, only rotating to adjust to their target's movements. Moving out of their line of sight, such as hiding behind a wall or using a lift, will break their lock and cease their firing, and they will be on the move to seek out their foe.

Its reliance on a bullet firing weapon makes the Mastermind susceptible of engaging into monster infighting both with other creatures and its own similars. Notably, MAP20 - "Gotcha!" in Doom II revolves around the possibility for the player to trick a Spider Mastermind and a Cyberdemon into fighting each other.

Their aim is also much better than the Former Commando, who shares its main mode of attack. The Doom II manual refers to the masterminds gun as 'a super chaingun'. Unlike the Arachnotrons' plasma shots, the Mastermind's bullets are impossible to strafe through and avoid; however, at a very long distance, the scatter of the spider masterminds chain-gun will cause the bullets to either hit the ground, or miss left or right of the player. In Doom Episode 3, level 8 'Dis' it is possible to set the mastermind firing, then run to the other side of the map, therefore the mastermind misses the player with almost every bullet, making it very easy to kill the mastermind and win the game.

While some concept art shown before the release of Doom 3 suggested the Mastermind may appear in the game, neither this creature nor the Arachnotron (to whom that concept art belonged) were ultimately featured in Doom 3, rather being replaced by the Vagary. The only available Spider Mastermind concept art is included in the book The Making of Doom 3.

Similarly to the game, in the Doom novels a Mastermind leads the invasion of Phobos and Deimos, with several more on Earth. They are relatively unchanged in appearance with the exception of a protective crystal dome over the brain. Also, they can talk, encase humans in cocoons and telepathically force a person to see their worst fears as a form of torture. Despite their intelligence, they are easy to anger and will kill their own forces. They are called "Spiderminds".

The Spider Mastermind does not appear in Doom 64 or Doom RPG.

The Icon of Sin
The Icon of Sin (also called Baphomet) is the final boss of Doom II and both chapters of Final Doom. Its image appears in the original Doom on numerous pieces of stone tablets, although it is never an enemy in the game. The Icon of Sin takes its name from the final level of the game, in which it is fought.

The Icon of Sin itself is a large demonic goat-like head set in a wall. This demon, the largest in the Doom series, continuously projects skull-faced cubes from its exposed brain. Upon landing, these cubes spawn monsters to attack the player. It cannot summon Cyberdemons, Spider Masterminds, or zombies. If a cube lands on the player, he will be immediately telefragged, even with an invulnerability powerup or the God Mode cheat. This is only if the player fights the icon in level 30. Using level editors, one can place the icon in levels other than level 30. If a player is at the same spot when a cube lands in any level other than 30, he or she will merely be stuck to the spawned monster. This is because of a hard-coded change in level 30 that allows monsters to telefrag, which affects all monster teleportation in the level. In normal play, the player can only defeat the Icon by shooting rockets into its exposed brain. Its size is further hinted at in part of the Doom II epilogue: "The monster shrivels up and dies, its thrashing limbs devastating untold miles of Hell's surface."

The Icon itself is not a true monster, but merely a static wall texture. Using the noclip cheat code, one can enter The Icon of Sin and see the "brain". Inside, there is a sprite of lead game designer John Romero's head impaled on a spike. It is within the splash damage radius of the rocket launcher, and damaging the head is what kills The Icon of Sin. It is not the head however that spawns the monster cubes. These are created by an invisible monster placed right at the entrance to this chamber (the hole in the big demon's forehead) in front of the Icon's brain. It sends the cubes to one of about 10 spawn spots placed on the map. If no spawn spots are placed on a custom map, the Icon of Sin cannot spawn monsters. The arcane chant the Icon of Sin speaks is actually John Romero speaking "To win the game, you must kill me, John Romero!", distorted and reversed.

In Doom II, The Icon of Sin may have been the mastermind behind Hell's invasion of Earth (in a way similar to the Spider Mastermind's involvement in the first game), and it certainly was the Icon of Sin that was bringing forth all the monsters. In the Plutonia chapter of Final Doom it serves as Hell's gatekeeper. In the Evilution chapter of Final Doom, it is simply referred to as the "demon-spitter". Its Baphomet moniker is derived from a remark made in the Final Doom manual - that "the Spider Mastermind and Baphomet no longer seemed to threaten". Although not explicitly stated, this reference to 'Baphomet' is generally accepted as being Doom II's Icon of Sin; certainly, the monster's head resembles that of the demon Baphomet.

The Icon of Sin does not appear in the Doom novels, as the novels replaced the idea of demons from Hell with a genetically altered alien invasion. However, in the second novel, Hell on Earth, the main character witnesses demons painting a head on a wall, which somewhat resembles the Icon.

The Icon of Sin does not appear in Doom 64, as the demons were resurrected as opposed to created, at the hands of the Mother Demon. It also does not appear in Doom RPG. They also don't appear in the PlayStation versions of Doom and Final Doom.

Wolfenstein SS
The Wolfenstein SS soldiers, based on the Schutzstaffel enemies from Wolfenstein 3D, only appear in the two secret levels of Doom II, which are based on Wolfenstein 3D maps. They have 50 HP and drop clips when they die. Their submachine weapons appear to be semi-automatic, firing faster than the pistol or Former Human Zombies, but slower than the chaingun. These soldiers speak the same German lines as their Wolfenstein 3D counterparts, but with a different, higher pitched voice. Also, unlike their tough, deadly equivalents from Wolfenstein 3D, Doom ' s SS soldiers are notoriously inaccurate, hitting the player or other monsters with the same likelihood.

The SS soldiers do not appear in the German release of the game, since the Wolfenstein 3D themed levels have been omitted, owing to the Nazi content they feature. These levels are also missing from the Playstation version of Doom, where different secret levels are used in their place, but are featured in the Game Boy Advance release of Doom II, though the images of Adolf Hitler and other Nazi symbols were cut.

Design
Adrian Carmack and Kevin Cloud were the chief artists behind Doom. Additionally, Don Ivan Punchatz was hired to create the package art and logo, and his son Gregor Punchatz created some of the monsters. A mixed media approach was taken to the artwork. Most of the sprites were drawn by hand, but some of the characters were digitized from sculptures. These were the player character, the Cyberdemon and the Baron of Hell, all done in clay by Adrian Carmack, and the Arch-Vile, the Mancubus, the Spider Mastermind and the Revenant, created in latex and metal by Gregor Punchatz. The sculptures were photographed from five to eight different angles so that they could be rotated realistically in-game, and finally touched up, colored and animated digitally with a program created by John Carmack, the "Fuzzy Pumper Palette Shop".

Reception, criticism and legacy
Kristan Reed of Eurogamer praised Doom for "incredibly stylish" character design, and Peter Scisco of GameSpot called the enemies of Doom II "pleasingly grotesque". Doom has been criticized for using satanic imagery in its enemies. CNN editor Steven L. Kent stated that the demons' deaths have a "repetitious cartoon quality", in contrast to movies where the characters "often seem to suffer and die slowly". Chris Charla, editor-in-chief of Next Generation Magazine, stated that Doom's use of satanic imagery in enemies (and violence) was copied by many others in attempts to be successful; "people were trying to 'out-Satan' Doom".