Optimus Prime, known as the leader of the Autobots, was originally a civilian by the name of Orion Pax on the planet Cybertron. He was rebuilt by Alpha Trion and given the Autobot Matrix of Leadership transforming him into Optimus Prime. In the original series, Optimus transforms into a flat-face truck with a trailer that converts into a combat deck. He is also accompanied by Roller a small non-speaking robot on wheels used for scouting. In all iterations of the Transformers, Optimus embodies righteousness and lives to protect Earth and the universe against the Decepticons.