Robotoid

The Robotoid was a relic from a civilization that had visited the planet Priplanus long before the Robinsons landed. Found and repaired by Will Robinson despite the Robot's warnings, it soon proved itself more versatile and useful than the Robot. Unlike a robot, a robotoid had the faculty of free choice and was able to operate outside its programmed functions. Unknown to the Robinsons, the Robotoid re-established contact with its original masters in order for them to invade the planet. In the end, it was destroyed by the Robot before its masters could invade.