The Maggot is a new enemy in Doom 3. Maggots have two heads and two long black tongues (one for each head). Their back is hunched and consists of two large, tumor-like bloody stumps with retracting barbed bones protruding from them. The Maggot alternates between approaching on all "fives" (since they have five limbs) and walking upright on its back legs, the latter commonly being used when close to the player. It may be interesting to note that each hand has a different shape: one is nothing more than a flat stump, one is a pinching claw and one is a simple human-styled hand. Maggots are possibly a cross breed between an Imp and a Wraith, since they can perform a leap attack and hunches. Saying that, Maggots only have melee attacks and also do not have falx-like arms like a Wraith does.
Only able to perform melee attacks, Maggots either rush up to the player to rend at them with their claws or perform a long-range leap which can cause significant damage and is nearly impossible to dodge.
Despite their size and mobility style, they are not known to leap as much as an Imp does, and are even weaker than an Imp. Even when standing next to each other, they dwarf Imps. A single Shotgun blast or a short burst from the Machine Gun or Plasma gun can easily kill a Maggot. Maggots have a tendency to run up to the player on the back legs then quickly crouch back down, so that the player can easily miss the first shotgun blast. A good strategy is to simply aim a little lower when they charge, or simply shoot them with the shotgun while they're leaping. Another good strategy is to use the Machine Gun or even the Pistol to kill them, since they have very low hitpoints. It is also a good idea to, later in the game, use the Chainsaw on them, considering that they are melee-attack enemies only.
Maggots make their debut in Alpha Labs Sector 1, where the player encounters a scientist who was pulled up to the ceiling and had his body split open by a Maggot. Upon the player's presence, the scientist begins to scream frantically, causing several Maggots to show up from different spots of the room and surround the player.