Servo robot

Servo Robots were a type of robot, possibly powered by servos, used by Humans in the 21st century. One Servo Robot was in control of and piloted the Silver Carrier, where it attacked the Doctor and Jamie while in orbit of Space Station W3. (DW: The Wheel in Space)

The Krotons that landed on the Gond planet encountered a Servo Robot and, by mimicking it, were able to achieve semi-sentience. (DW: The Krotons)