The biggest most powerful transformer of all.I will go into some background about him.Millions of years ago there were cosmic gods of the universe.1 of these beings called primus had to destory the last of the darkgods.Unicron the caous bringer.Not a easy job.They fought had for a long time.Primus was no match for unicrons stength and hand to hand combat.Primus to the battle to the astroplain but faired little better.Primus had knowage thou.He tricked unicron in to in prisoning his sprit.In a gain t ironore astroid primus was in prisoned in another astroid.Still over time primus learned he could shape the astroid any form he wanted.Unicron also learned to do this.But shaped astroid into a plaint that could eat other planets,moons and even stars.He can tranformer into a likeness of his oldself.He was the main villian in the transformer movie.His voice was done by orson wells.