First Scientist

The  was one of two Sensorite scientists who helped the First Doctor test the water on the Sense Sphere for poison, specifically atropine. When they found the poison, they helped the Doctor with an antidote. He showed the Doctor to their aqueduct, and later showed Ian Chesterton and Susan Foreman the way to the aqueduct to rescue the Doctor.

He and the other scientist also worked to cure John of the madness caused by the Sensorites' telepathic attacks on his mind. (TV: The Sensorites)