Character description from package back: 

Rebuilt with parts cannibalized from other Decepticons, Megatron rises once again to lead his army.  Though the AllSpark destroyed him once, he can now feel its power coursing through his circuitry.  It calls him to seize his rightful place as ruler over the puny planet on which he was imprisoned and destroyed and from which he will launch his conquest of the universe.  Optimus Prime is all that stands between him and victory and the Autobot leader has done a poor job of hiding himself.  At long last Megatron knows exactly where his enemy is and he has power enough to destroy him.

Bibliography of significant appearances: Revenge of the Fallen, movie, comics and novels.