Starcraft

Cerberus from StarCraft 1
Always dug him and the Precursor campaign, even if it is piss-easy, it's cool having Duke in his siege tank.

Head of the Cerberus Black Ops Unit, Cerberus is an intelligent A.I developed specifically to handle the "dirty" jobs few human commanders would have the stomach for. A loyal cog in the Terran Confederacy up until its demise, despite numerous members of his unit confirmed as dead or otherwise accounted for, Cerberus himself has evaded capture by the Terran Dominion, and even notice by most other powers in the Koprulu Sector. Dogmatic and only knowing how to follow orders given to him by long-dead masters, he'll stop at nothing to see his goals achieved, and the enemies of the Terran Confederacy dead.

Traveling about from within the confines of his labyrinthine body, even an aging Confederate Science Vessel meets little resistance from straggling Zerg patrols.