Makra'Thon

Makra'Thon was a general of the Khellians in the 29th century. Makra'Thon attacked a human colony ship in order to feed on its inhabitants, however his troops were killed when Fifth Doctor destroyed the colony ship. Makra'Thon then attempted to hunt down the Doctor, during the hunt he ate Auntie, the leader of the colony ship. In a confrontation with the Doctor, Auntie detonated an explosive device inside Makra'Thon's stomach, killing him. (AUDIO: Three's a Crowd)

Behind the scenes
The vocal treatment on Richard Gauntlett's voice makes Makra'Thon virtually indistinguishable from James Earl Jones' Darth Vader.