Imp

"Just a few days ago, you were probably swapping war stories with one of these guys. Now it's time to swap some lead upside their head."

- Doom instruction manual

The Imp is a human-sized humanoid demon, the most common opponent encountered in id Software's IWADs. The Imp is the most common demon/humanoid-like enemy in Doom games, thus being considered the "backbone" of all hellspawn in the entire franchise.

The Doom instruction manual says:
 * You thought an imp was a cute little dude in a red suit with a pitchfork. Where did these brown bastards come from? They heave balls o' fire down your throat and take several bullets to die. It's time to find a weapon better than that pistol if you're going to face more than one of these S.O.B.s.

Physical Appearance
It is leather brown in color, with blood-red eyes and mouth, several white bony spikes on its body, and equally white claws on its hands and bare feet.

Combat Characteristics
An Imp will make a loud, serpentine hiss in two different pitches when it spots a player. When killed without being gibbed, it either lets out an animalistic moan of pain ("Nuuuh!") or a distorted gurgle ("Eeergh!") as enormous holes open up in its midsection and face (most notably on its forehead), unleashing plentiful amounts of blood as it falls onto its back.

Tactical Analysis
Imps attack by hurling a single fireball, which inflicts direct projectile damage; at melee range, it employs a clawing attack. The Imp moves slowly, as do its fireballs. The player should practice until evading both sorts of objects becomes completely straightforward (except perhaps under highly unusual circumstances such as a teleportation trap, in close quarters or when surrounded).

An Imp can usually be killed by a single shotgun shell and often by six bullets. As the citation above implies, facing multiple Imps with a pistol takes concentration, but it can be done, given sufficient maneuvering room and adequate footwork on the player's part. In fact, the Imp's relatively high pain chance sometimes makes it difficult for it to retaliate when damaged often.

Imps often come in packs, and the super shotgun or rocket launcher are both particularly effective here. While the standard shotgun is not completely reliable in dispatching an Imp per shell, a blast from the super shotgun usually brings two down and, when well-aimed at "clumped" packs, three. The rocket launcher can take out entire crowds with little difficulty if used carefully.

Melee against an Imp should usually be avoided by novices as it is much trickier than against a Demon, as the imp is quicker with its clawing attack than the generally less dexterous demon. The chainsaw takes only a bit of time to dispatch an imp, so it is convenient against a single enemy, but the player risks being surrounded if there are several imps. If the encounter takes place in a large open area, hit-and-run tactics with the berserk fist are safe and effective, as long as the player is not under fire from different sides.

In the Nightmare! skill levels, like all other monsters, Imps become ultra agressive and don't stop shooting after they start. Their projectiles become significantly harder to dodge especially in packs. Their projectiles also move 50% faster and become as fast as a Baron of Hell's.

Although its ranged attack and hit point total give it an advantage against the lesser zombies, the Imp can easily find itself outmatched during monster infighting. A single Imp fighting a shotgun guy may yet call victory, but a Demon or Spectre can almost always overpower the first two or three imps they engage in melee, and a few blows from even tougher monsters, such as a Cacodemon or a Baron of Hell, will more than likely put an Imp out of its misery.

Data
Attributes = Melee Range
 * -|Bits list =
 * -|Sprites & sounds =
 * -|Melee/Range attack =
 * -|Scratch damage =
 * 1) These tables assume that all calls to P_Random for damage, pain chance, blood splats, impact animations, and backfire checks are consecutive. In real play, this is never the case: counterattacks and AI pathfinding must be handled, and of course the map may contain additional moving monsters and other randomized phenomena (such as flickering lights). Any resulting errors are probably toward the single-shot average, as they introduce noise into the correlation between the indices of "consecutive" calls.
 * -|Fireball damage =
 * 1) These tables assume that all calls to P_Random for damage, pain chance, blood splats, impact animations, and backfire checks are consecutive. In real play, this is never the case: counterattacks and AI pathfinding must be handled, and of course the map may contain additional moving monsters and other randomized phenomena (such as flickering lights). Any resulting errors are probably toward the single-shot average, as they introduce noise into the correlation between the indices of "consecutive" calls.
 * 2) Assumes that direct hits are possible, which does not occur in any stock map.
 * 3) Hardcoded exception to infighting negates damage (excepting indirect damage caused by exploding barrels).

Appearance Statistics
In the classic Doom, the Imp is first encountered on these maps:

The IWADs contain the following numbers of imps:

Doom 64

 * Main article: Imp (Doom 64)

The Imp is featured in Doom 64, first appearing in MAP01: Staging Area, though with a sleeker appearance, only having noticeable spikes along its back.

A more powerful variant known as the Nightmare Imp is also one of the new monsters in the game.

This version of the Imp also features discrete animations for melee attacks versus ranged attacks, similar to the Revenant in other games. This means that unlike other versions of the game, the Imp will not throw a fireball if his melee attack misses the player (since in other versions, the attack type - fireball or melee - is determined by the victim's proximity at the end of the attack animation).

Doom RPG

 * Main article: Imp (Doom RPG)

In Doom RPG, the Imp appears as a class of monster. There are three variations, identified by color:
 * Impling (green)
 * Imp (normal colors)
 * Imp Lord (red with green eyes)

Imps are most susceptible to attacks from shotguns.

Trivia

 * Imp's dying voice is simply a Bactrian camel mating call.