Grimlock is a Tyrannosaurus rex in charge of a small, three-mech group of dinosaur transformers known as the Dinobots. Born from a fusion of Earth and Cybertronian technology, with some AllSpark intervention thrown in, he's a force to be reckoned with. A little short on brains (at first he didn't actually realise he was a Transformer) and a lot short on temper, Grimlock's answer to a problem is usually the simplest: squash it, slash it, bite it, burn it, eat it, or a combination of above actions toward it.