Therovian

Therovians were a technologically advanced humanoid race native to Theros. They were approximately four feet tall with bald heads and large eyes.

At some point in their history, a plague began afflicting the Therovians, gradually weakening most of the population. Grig, one of the few left unaffected, was sent on a mission by the President to find a cure. With the aid of the First Doctor, John and Gillian, a cure was found on Ixon and delivered to Theros. (TVC: The Therovian Quest)