Optimus Prime (known as Convoy in Japan) is a fictional character and the protagonist of the Transformers universes. He is the leader of the heroic Autobots. Optimus has become the most well-known character of the series. The Original Cartoon Transformers G1 was voiced in english by Peter Cullen, Roger C. Carmel in the episode Masquerade only.
His untransformed form is that of a Peterbuilt transfer-truck in the live-action movie.