Repthon

 was one of the blue-fronded Intransigents of Smorg and a representative of a planet that visited Akimus Makassar. Makassar explained to Repthon that he was more of a spokesperson to the Units than a leader and that his mask was larger than other Units' as it served as the "processing centre". Makassar placed Repthon and the other representatives in a mask to take command of them, but the Ninth Doctor freed his control by placing another Unit's mask on Makassar's face, creating a loop. (PROSE: The Masks of Makassar)