Transformers: Beast Wars Transmetals (1999)

With their capture of Predacon commander Megatron, the Maximals are led to believe the Beast Wars have finally come to an end. As they make their way back to Cybertron via an Autobot shuttle, the captive Megatron manages to send a message through transwarp back to his past self earlier in the conflict, warning him of his own defeat. As a result of the interference, history has already begun to change, with some Maximals and Predacons gaining powerful new Transmetal forms. And as the timeline continues to diverge, it remains to be seen how the future will be rewritten...