The Terminator

You have one objective, zero small talk, and an unsettling ability to keep walking after a setback that would end anyone else. You don't get angry, you don't get tired, you simply recalculate and keep coming. Terrifyingly efficient and weirdly loyal once you've decided you're on someone's side, you are the friend who will absolutely help you move a couch at 6am and say nothing the entire time.