The Fallen, originally known as Megatronus Prime, is a major antagonist in the Transformers franchise. After originating as a major antagonist of Dreamwave Productions comics, The Fallen also served as a major antagonist in the Transformers Cinematic Universe, specifically being the unseen overarching antagonist of the 2007 live-action film Transformers, and the titular main antagonist of the 2009 sequel Transformers: Revenge of the Fallen.
Originally one of the original Primes, the Fallen went rogue and founded the Decepticons, and became the master of Megatron, seeking to rule the universe and wipe out both the Autobots and the human race.