After spending the better part of the past 20 years cranking out live-action Transformers movies, the franchise has finally returned to its animated roots with the critically acclaimed Transformers One.

"Transformers One" director Josh Cooley channeled his inner kid for the film's big moments, from old-school cameos to an "awesome" post-credits scene.

Transformers One” is the untold origin story of Optimus Prime and Megatron, better known as sworn enemies, but once were friends, in theaters beginning Sept. 20.