Skullitron

Skullitron is one of the legendary Knights of Iacon and a sworn protector of the Staff of Merlin. The past millennium or so haven't been kind to him.

His face came off, for example.

The Last Knight Flim
Skullitron lay rusting and inactive aboard the Knights' ship deep beneath the Atlantic Ocean. Awakened from his repose by the arrival of Viviane Wembly and Cade Yeager, the disoriented and decomposing Knight violently attempted to defend the Staff of Merlin from the human interlopers, but the arrival of the Transformers Reaction Force and ensuing battle led to the severely damaged Skullitron plunging down a chasm into the ship's bowels.