Optimus Prime is the primary protagonist of the live-action Transformers film series, appearing in the first film, Revenge of the Fallen, Dark of the Moon, and Age of Extinction sharing the role with Sam Witwicky and Cade Yeager. Originally a peaceful Cybertronian scientist and the very last Prime of the Dynasty, Optimus and his team of scientists were studying the mysterious Allspark until they were betrayed by their security unit, the Decepticons, and its now corrupted power hungry leader, Megatron. Naming his squad of scientists Autobots, he used his team to fight the tyrannical Decepticons in order to stop them from getting the Allspark's awesome power. He is based off his original incarnation with the same name.