K1
The Experimental Prototype Robot K1 was a robot designed and built by Professor JP Kettlewell of Think Tank. It was to eventually replace Humans in difficult and dangerous tasks, including mining operations, activities involving radioactive material, and thousands of other tasks.
It was created when Kettlewell discovered a metal, which he called "living metal", that could grow with the robot. Though the robot was very big, it was very good and manipulating devices and could even operator the disintegrator gun that it was given by Think Tank.
It had a very literal mind and was fitted with Prime Directive, based off of Kettlewell's own mind, keeping it from killing Humans, and should it kill humans, it would become confused and go mad.
The people of Think Tank, who were part of the Scientific Reform Society, used the robot to steal the components of the disintegrator gun and destructor codes for the missiles of America, China, and Russia. When Sarah Jane Smith meet it, she cared for it being confused by the orders it had to kill.
When it killed Kettlewell, it developed an Oedipus complex and took Sarah captive, planning to keep her safe as it launched the missiles. It would destroy mankind and build more machines like itself, claiming that machines do not lie.
The countries activated their fail safe codes and stopped the launch. Attempting to escape, the Brigadier fired the disintergrator gun upon the robot, but the effect made it grow to enormus size. It took Sarah and placed her on top of a building, away from harm as it attack UNIT.
The Doctor, having created a metal virus that Kettlewell also discovered, took a bucket of the liquid and, riding in Bessie, splashed the robot with the virus. It ate away at the robot until it returned to its normal size and disintergrated. (DW: Robot)
Later, in the 26th century, Kettlewell's designs for the robot were found and many K1s were constructed, though they all went mad again. (BFBS: The Relics of Jegg-Sau)