Fan Casting Giganaut in Transformers: Rise of Prime

Ruler of Planet Dinobot, Giganaut transforms into the apex predator of prehistory: the powerful Giganotosaurus, bigger and stronger than his son Grimlock's alt. mode the T-Rex. Onyx Prime came to a deserted planet where he made the Dinobots, his most powerful race. GIganaut was his first Dinobot, and Giganaut proved more powerful then Onyx himself, so the beastly Prime let Giganaut rule the planet he had populated for him and the Dinobots. And Giganaut is still king until death comes.