Optimus Prime (Robots in Disguise)

Optimus Prime was the leader of the Autobots, chosen by Alpha Trion to receive the Matrix. This made his brother, Ultra Magnus, furious with jealousy, leading him to leave Cybertron. Prime eventually travelled to Earth with a group of Autobots, where they blended in with Earth vehicles to covertly protect the population. Prime eventually had to lead the Autobots into battle against Megatron to stop him from acquiring the O-Parts- and through them, Fortress Maximus. Magnus came to Earth to take the Matrix from Prime, only to wind upfusing with Prime to become Omega Prime when he made the attempt. In a final battle within the Earth's core, Omega Prime was able to defeat the empowered Megatron- Galvatron- once and for all.

Japan

In Japan, Optimus Prime was known as Fire Convoy.