Commando/Doom II

The Chaingunner (sometimes called Heavy weapon dude) is a former human who carries a chaingun. The chaingun is dropped when the chaingunner dies and can be picked up by players. Although a chaingun is fired, the speed of fire by this enemy is slower than the speed of a player firing a chaingun, and the sound effect is that of the shotgun. When a chaingunner begins firing, he doesn't stop (he turns around very fast) until he will kill his target, his target will escape from his range of fire or he will die. Similar behavior can be observed at Spider Mastermind.

Internally the Doom source code gives the Chaingunner the type name MT_CHAINGUY. The sprites for the Chaingunner have the prefix CPOS.