Imp (Doom 3)

The imp in Doom 3 is humanoid in shape, has a grey skin with bony scales on its arms, and an array of ten eyes. This monster is tall and aggressive, standing a full head taller than a normal human. It emits a high-pitched screech when it sees an enemy. Imps are extremely common in the game, often being teleported into an area after a player enters it, or performed some action. The imp is the most frequently encountered demon in the game, appearing 15 to 30 times more often than other demons. It has acrobatic capabilities, able to pounce at the player, walk up or down walls on some occasions, and crawl along catwalks.

In Hell, imps have a different appearance than those encountered on Mars, appearing to have been flayed. This fact leads some to think they are naturally skinless and their bodies adapted when exposed to the Martian environment.

Combat characteristics
The imp generally walks slowly towards the player, but it can climb walls as well (note that all imp wall-crawling events are scripted actions for when an imp first enters an area. Once on the ground, imps are limited by their A.I. to simple walking). Most of the time they will ambush the player, hiding behind doors or climbing on roofs. They can either throw explosive fireballs from their hands that travel in an arc, attack with their claws, or pounce forward in a scratching attack. Occasionally, they will pounce sideways when hit to dodge additional fire.

The Doom 3 imp can in some ways be seen as tougher than its classic counterpart, considering its ability to leap at the player in a surprise attack, increased agility, and fireballs whose smoke can easily obscure the player's vision, but some of Doom 3's weapons are more powerful: the shotgun and the chaingun are particularly effective.

Overall, the imp is an average mid-level demon, tougher than Z-Sec soldiers or "pest" demons such as trites or lost souls, but still relatively easy to bring down. They are higher than maggots or wraiths in terms of combat threat due to their projectile attack.

Tactical analysis
The shotgun is usually the best weapon to use against individual imps as a well-placed point-blank shot can kill it instantly, but players should be wary of their tendency to suddenly drop to all fours and pounce. Players should aim for the upper part of their bodies and move in as close as possible as the imp's thin stature makes it difficult to hit it with the full spray of pellets even at the slightest distance. 15 to 20 rounds of machine gun fire can also bring down an imp, and has the advantage of being able to mow it down from long range, outside the range of its pouncing and melee attacks. Against multiple imps, use of more powerful weapons such as the chaingun and plasma gun is advised.

Evading imps' fireballs is fairly easy once players become accustomed to their traveling arc. Moving forward and ducking whenever the imp tosses its projectile is the easiest way to avoid being hit. In more open areas, strafing sideways also works if there is enough space to do so. Their fireballs have minimal splash damage, causing a couple points of damage, so take that into consideration when dodging. If you have the grabber in Resurrection of Evil or The Lost Mission, you can catch the fireball and shoot it back at the imp - a direct hit should kill it. It will be one of the first uses you will have for the weapon; the soldier who gives you the grabber is shown doing just this and tells the player about it before turning over the weapon.

UAC Research Notes
These notes can be downloaded to the Player's PDA during the course of the game in Delta Labs Level 2b:

Specimen 197 - Imp

''This humanoid's long and muscular limbs make it extremely agile as a biped or quadruped. Its long and sharp claws allow for climbing steep surfaces. A configuration of 10 eyes provides this creature with a wide field of vision and the ability to see with clarity in low-light environments.''

Specimen 27 - Imp (partial)

''-Left forearm amputated for biological study.  Researchers are currently studying how this creature is able to manifest and throw an explosive plasma projectile from its hands.''

Doom 3
The imps are by far the most common enemy in the game, found in almost every level in the game, except Delta Labs - Level 4 and Delta Complex. The difference in the amount of imps in BFG Edition is tiny.

* Some imps in these levels are spawned by arch-viles, thus their amount may vary. In these tables only the amount of distinct spawn points is shown.

This tally doesn't include Primary Excavation level because the amount of imps is infinite in it.