Alien

Someone who is wrong about something but will continue to convince you that YOU are wrong until you're forced to agree to get out of it. Typically these people all look skinny and alien like.

Alex: "The earth is flat and its been proven". Me: "How has it been proven? The earth is not flat" Alex: "Dude the earth is like totally flat what are you talking about dude are you retarded do you see a curve?" Me: "SHUT UP ALIEN."