New Transformers 3 Trailer: Why's Optimus Prime angry?Ray Wert4/28/11 6:15pm2282EditPromoteGo to permalink Optimus Prime doesn't sound real happy about the American military hiding stuff about giant robots on the Moon. Now somebody's got to clean up the mess — and it's him. Or it. Or whatever. You know, because he's a giant truck that turns into a robot.