Big, Shaq sized Transformer who eats up any planet or moon in it's path. Basically the baddest mofo in the universe. He has a "planet mode" in which he consumes planets and also a robot mode. First appearance was in the 1980's Transformers Cartoon Movie, in which he rebuilt a defeated Megatron into Galvatron, and in return he made Galvatron his bitch. But at the end of the film Hot Rod turned into Rodimus Prime via The Matrix (Allspark in live movie) and Rodimus used The Matrix to destroy Unicron.
Unicron better appear in the next live movie.
Also note that Unicron had epic voice. And oh ya, the movie takes place in the year 2005, so it all happened 2 years ago...
Unicron:"For a time…I considered sparing your wretched little planet Cybertron. But now, you shall witness...its dismemberment!"
RE1000: "What's that thing eating the moon up there in space? Ohhhh it's The Unicron!"