Robot Masters

''In 2004, Optimus Prime is alerted to a disturbance at the gates of Autobot City; a force of Decepticons led by a vicous new enemy, a tyrannosaurus rex calling himself Megatron!! Autobots and Decepticons from across the eras have converged on this time to clash over the newly-discovered energy source solitarium!''

Robot Masters is a Takara sub-line released in 2004 consisting mainly of redecoes of previously-released toys with several all-new molds of popular characters thrown into the mix.