Beast Wars was about Transformers who could turn into animals. They looked like real animals, but they were robots in disguise. The good guys were called Maximals, and their leader was Optimus Primal. The bad guys were called Predacons, and their leader's name was Megatron. (He was a different Megatron from the Decepticon leader.) In the story, the Maximals and Predacons crashed on Earth a very long time ago, but they did not know where they were. Also, there was too much energy on the planet and it hurt their bodies. They turned into animals to protect themselves from the energy. They could only turn into robots for a short time before the energy started to hurt them.