Megatron is the main antagonist of the Transformers media franchise produced by the American toy company Hasbro and the Japanese toy company Takara Tomy. He is the tyrannical leader of the Decepticons, a villainous faction of alien robots that seeks to conquer their home planet of Cybertron and the rest of the known universe, and serves as the archenemy of Optimus Prime, the leader of the rival Autobot faction. As with all Cybertronians, Megatron can disguise himself by transforming into vehicles or weapons. His alternate modes have included a Walther P38 handgun, a particle-beam weapon, a telescopic laser cannon, a Cybertronian jet, and various tanks, depending on which continuity he is depicted in.

Transformers is a media franchise produced by American toy company Hasbro and Japanese toy company Takara Tomy. It primarily follows the heroic Autobots and the villainous Decepticons, two alien robot factions at war that can transform into other forms, such as vehicles and animals. The franchise encompasses toys, animation, comic books, video games and films. As of 2011, it generated more than ¥2 trillion in revenue, making it one of the highest-grossing media franchises of all time.