Beast Wars: Transformers is an computer-graphics animated program, created by Canadian company Mainframe Entertainment. It is among the best of not only Transformers series, but is one of the best cartoons of all time.
Taking place both before and after the Generation One-era of Transformers (Hooray, time travel!), this series both used previously-established continuity and told detailed, intricate stories of its own.
War between the Maximals (descendants of the Autobots) and the Predacons (descendants of the Decepticons) continues to rage, despite the seemingly-long-term reign of peace on the Transformers' home planet, Cybertron. While the Axalon, a Maximal ship, is exploring the Universe, it is attacked by the Predacon ship, the Darksyde. The two ships are sucked through a wormhole and transported to prehistoric Earth.
The Transformers aboard their respective ships do what Transformers do, and take alternate modes - But instead of the usual cars and jets, these Transformers all take the forms of Beasts. And so, the Beast Wars begin!