Arcturus (The Curse of Peladon)

Arcturus was the Arcturan delegate to Peladon when it applied for membership in the Galactic Federation.

Biography
Arcturus aided Hepesh in attempting to prevent Peladon from joining, secretly planning for his world to exploit the planet's mineral wealth afterwards.

He attempted to kill the Third Doctor at the end of the Time Lord's fight with the King's Champion Grun in a trial of strength, but was destroyed by the Ice Warrior Ssorg with a blast of his sonic gun; Ssorg acting to defend the Doctor. (TV: The Curse of Peladon)