Grimstone has always dreamed of power and the privilege it brings. Despite his hunger for power, however, he has always considered the needs of others before himself. He believes it is the responsibility of the powerful to protect those less fortunate — a belief he intends to aggressively enforce now that he has his own Power Core team.
- Grimstone with Dinobots(Commander, 2010)
- Released as part of Wave 4 of the 5-pack, Grimstone transforms into a Styracosaurus. In humanoid mode, he is quite a porker, he has a large body and very wide hips. In combined form, the Dinobots attach via the blue pegs. In this mode, Grimstone's head is quite large and tall, this is because its formed out of the Triceratops head.
- Grimstone's box misidentifies him as a Triceratops.