A TroopAttack

A_TroopAttack is a code pointer used in the attack animation for the Imp.

is used for both of the Imp's methods of attack. If the imp is within melee range of its target, it does a random amount of damage to its target and plays the sound effect DSCLAW. Otherwise, it launches a fireball (object of type ) towards its target. If the monster has no target, nothing happens.

The naming of this code pointer is a somewhat confusing artifact of Doom's development process where the Imp was initially called a "troop" before the addition of the Zombieman (aka Trooper).

Uses
The  code pointer appears in the following states in Doom's state table:

Example
The following is an example of how to set the  code pointer in a Dehacked file:

Pointer 21 (Frame 34) Codep Frame = 454

Or using BEX syntax:

[CODEPTR] Frame 1234 = TroopAttack