Grindor was a massive hulking Decepticon who, like most Decepticons, was loyal to Megatron. He was a master stratagist, and always planned ahead of his enemies. Except for that one guy. Yeah, that one didn't go so well. Grindor died, for example.
He later joined both Megatron and Starscream in the forest hunting Sam. They did not count on Optimus Prime being present with the boy and the trio began to fight the Autobot leader. Grindor was not treated to well by Optimus, who used his blades to slice off one or Grindors arms, and slashed him in the chest, Grindor fell back for a bit, but rejoined the fight, only for Optimus to jump on top of him, and use his swords to rip Grindors head apart. Prime then jumped dow, pulling the corpse of Grindor down with him.