The animated origin story of Autobot leader Optimus Prime and his Decepticon rival Megatron will come to the big screen this September in Transformers One, with Chris Hemsworth and Brian Tyree Henry voicing the friends turned enemies. The first trailer for Transformers One sets the tone for the Cybertron-set adventure, with Prime (then known as Orion Pax) and Megatron being pretty chummy in a buddy comedy kind of way.