Galvatron

Galvatron is the leader of the Decepticons from Transformers. He's the rebuilt version of Megatron.

Though Galvatron doesn't make a appearance in Transformers x Evangelion but he was mentioned.

Transformers x Evangelion
Upon gaining the power of an Angel by possessing its body, Starscream mused about using his newfound power against Galvatron, but he first decided to get rid of Optimus Prime once and for all.