Spiderdemon

The Spider Mastermind (called also the Spiderdemon) is a die-hard creature, the boss of Episode III (Inferno) of Doom I. His weapon is a big machine gun that has the sound of the shotgun. When a Spider Mastermind 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 Chaingunner.