Grimlock is an Autobot with the role of Dinobot Commander who is powerful and stubborn and is often chosen to lead battles. He belongs to the group called Actionmasters which are based on both existing and new Transformers characters. The Actionmasters do not transform, but their weapons or vehicles do. In this case Grimlock's "Anti-Tank Cannon" transforms into a "long range mortar launcher" (according to his Tech Spec).

The Generation 1 Grimlock was released in 1990.