IMC robot

The IMC robot was a Mark Three servo robot used by the Interplanetary Mining Corporation to survey planets for mineral deposits. It was built like a small tank with two arms and a whirring sensor on top and was operated by remote control. However, the IMC could operate it as a killing machine if their goals were threatened. The robot on IMC's expedition to Uxarieus was used by Morgan to make it appear that giant lizards were attacking the colonists. He outfitted the robot's arms with fake lizard claws and used it to kill Eric and Jane Leeson. The robot nearly killed the Third Doctor as well, but he used the remote to deactivate it. (TV: Colony in Space)

Behind the scenes
In the original script and the novelisation, the robot was humanoid.