Sorgat

Sorgat is a friendly Tritovore who makes his first appearance in the first episode of Season 10. He normally communicates by making clicking noises, which is why the Doctors give him a translator, which he sometimes forgets to turn on.

Role
Sorgat is first seen coming out of his spaceship to trade with the people of Earth. The Tenth Doctor learns that Sorgat is bored with his life and wants some adventure, which the Doctors gladly give to him.

Sorgat proves to be quite invaluable with his technological skills and ability to understand other alien languages. He also helps the Doctors to thwart a plan by the Daleks to awaken a huge army on Spiridon.

He also takes part in the Cyber War on Weblus, where he helps to stave off the Cybermen. Unfortunately, he winds up being destroyed in the Season 11 finale by Azal, a Dæmon summoned by the Masters.