Talk the entire way through the exam. Read questions aloud, debate your answers with yourself out loud. If asked to stop, yell out, "I'm SOOO sure you can hear me thinking." Then start talking about what a jerk the instructor is.
Walk in, get the exam, sit down. About five minutes into it, loudly say to the instructor, "I don't understand ANY of this. I've been to every lecture all semester long! What's the deal? And who the hell are you? Where's the regular guy?"
Every now and then, clap twice rapidly. If the instructor asks why, tell him/her in a very derogatory tone, "the light bulb that goes on above my head when I get an idea is hooked up to a clapper. DUH!"
Every five minutes, stand up, collect all your things, move to another seat, continue with the exam.