Megatron is the evil leader of the Decepticons and archenemy of Optimus Prime. Megatron was a combat champion and outspoken voice against the corrupt government on Cybertron. His former intentions were good and attracted Optimus Prime whom he mentored. However, eventually Megatron became corrupt and Prime turned against him for good reason. Megatron can transform into various things, his most well known form being a handgun / cannon. In the 2007 Transformers film his alternate mode is a Cybertronian jet.