Nightbeat

Nightbeat is an Autobot detective. He fought in the Shadow Wars against the Shadow Minds, most notably during the battle of Balmorra. He survived the war and would plan the eventual assault to re-take Cybertron.

Loss of Head Incident
At some point, Nightbeat was beheaded but he somehow survived. A whinny human, who could somehow transform into a head, was used as a replacement for a while, until a new head was built for him. At some point, he was beheaded again and his body was somehow destroyed, as such he transformed into a head for a while, until a replacement body could be found.

Shadow Wars
During the Shadow Wars, he fought the Decepticon, Horri-bull in a fistfight and won, ripping off his rival's head. He also got shot in the head by Triggerhappy but survived. Man he gets a lot of head injuries.