Kamelion was a shape-shifting android which helped The Master escape from the planet Xeriphas. The villain used Kamelion, in the guise of King John, in an attempt to alter English history (The King's Demons), but was thwarted by The Doctor, who took the android with him. Kamelion spent most of his time exploring the TARDIS and learning about its systems. He had a mind of his own, but could be controlled by a superior intellect.

Sadly, The Master regained control of Kamelion and used him in another of his convoluted schemes. Kamelion, who realized that his inability to prevent himself from being used was a constant source of danger, asked The Doctor to kill him, and the Time Lord reluctantly complied (Planet of Fire).