Beast Wars: Transformers

Trapped on a primitive planet, two opposing factions, the Maximals and the Predacons, of Transformers, a race of sentient robots, fight over its precious Energon. Soon they discover that there are other forces at work on the planet - a powerful alien race that does not approve of their presence. And as they delve deeper into the planet's history, they uncover a terrible secret, one that must not be allowed to fall into the wrong hands, or their entire race's very existence could be threatened.