Raston Warrior Robot (The Five Doctors)

A Raston Warrior Robot was time scooped to the Death Zone on Gallifrey.

Biography
When the Death Zone was reactivated and four of the Doctor's incarnations were trapped there, the Third Doctor and Sarah Jane Smith encountered the Raston Warrior Robot by a cave entrance and had to remain still to avoid detection. A patrol of CyberNeomorphs appeared and the robot attacked them instead, firing a barrage of javelins into their chest-plates and destroying them all, allowing the Doctor and Sarah to sneak past while it was occupied. (TV: The Five Doctors)

Ryoth used the Time Scoop to send this same robot to the Eye of Orion, where it attacked the Fifth Doctor, Tegan Jovanka and Vislor Turlough. The Eighth Doctor joined them. By using the paradox known as Buridan's ass, the two Doctors approached it at the same pace so that both were equidistant from it. Unable to decide upon a target, as the Doctors' identical brain patterns meant that it was sensing the same target in two different places, the Raston Warrior Robot deactivated. It was reactivated when a Sontaran trooper kicked it. It killed the entire regiment but was itself defeated by Commander Vrag who, in his death throes, ripped its head off. However, it repaired itself after the Doctors had departed, and resumed guarding the area. (PROSE: The Eight Doctors)

The Raston Warrior Robot was confronted by Leela in a clean up of the Death Zone. Regarding it as a "worthy opponent," Leela ultimately terminated the robot and mounted its head on the wall of her kitchen. (AUDIO: Time in Office)

Legacy
Travelling through the caves of the Death Zone to save Borusa from the Dark Tower, the War Doctor and Cinder found various cave paintings which the Doctor speculated were depictions of himself throughout his lives, with one of the paintings depicting a figure "with bouffant white hair and a cape being chased by a silver robot". (PROSE: Engines of War)

Behind the scenes

 * Autons were originally planned to appear in The Five Doctors instead of the Raston Warrior Robot but, for unknown reasons, did not.
 * The Raston Warrior Robot was played by Keith Hodiak, who was an actor, but is more famous as a professional ballet dancer and instructor.
 * The Raston Warrior Robot costume is a re-paint of the Cyberman androids costume — a rather amusing turn of events, as the Cyberman androids were controlled by the Cybermen to do their bidding.