Grun was King Peladon's Champion. He was mute, possessed great strength, and was fiercely loyal to the King. At first he assisted Hepesh in his plans, but later realised that he had been misguided and helped the Third Doctor defeat the High Priest. (TV: The Curse of Peladon)

After Lord Axlaar threw King Peladon to the ground while trying to free the Doctor from his grasp, Grun was gunned down by Sslurn while attempting to protect the Doctor and King Peladon. (AUDIO: The Prisoner of Peladon)