Grimlock the leader of the Dinobots
Some Autobots wonder why Grimlock is even on their side. His disposition is much more suited to the Decepticons. After all, he values power and strength over wisdom and compassion, and furthermore, he doesn't really get along with most Autobots, but when push comes to shove, Grimlock will always fall in on the right side of the fence.
Interestingly enough Grimlock's default form is as a Dino, instead of transforming into a dino he transforms into this, his humanoid form.
Grimlock alt mode - Transformers Earth Wars