Megatron

Megatron was a random person who owned a fusion cannon and could transform into a gun. He fought Zev Raregroove, Malygos and Iron Man.

Later, Megatron mysteriously became a character in a video game, and fought Bumblebee in a level called Desert Massacre, when Muta, who at the time was being beaten up by the contents of Blackout's computer, appeared. Bumblebee then paralyzed Muta, allowing Megatron to KO Muta and blast him into the Autobots' war room.