Cambot is the robot that films Joel Robinson/Mike Nelson, Tom Servo, Crow T. Robot, and Gypsy aboard the Satellite of Love on TV's Mystery Science Theater 3000. He was constructed by Joel (both the character (in series continuity) and the series creator, Joel Hodgson) in order to allow Dr. Clayton Forrester/Pearl Forrester and Dr. Lawrence Erhardt/TV's Frank/Professor Bobo/Observer to watch the SOL crew watching the horrible movie of the week. We never see Cambot on the show outside of the opening credits (when he looks into a mirror) because he is the one filming the action. He rarely interacts directly with the crew. In episode 202, The Sidehackers, Cambot displayed a scoreboard during the movie. He's also been known to get misty lensed when cameras are damaged in the movie. He is also capable of displaying "Rocket Number 9", the rear exterior camera on the satellite.
Cambot has changed appearance several times over the years. There has never been an official in-series reason as to why this happened, but the off-camera reason is presumed that since Cambot is not an actively seen character, his parts were disassembled for use in other props. Whenever he was needed for new opening credits, he was redesigned to make use of available materials. Below is a list of his parts (taken from the Satellite News MST3K FAQ):
- Season 1: Some sort of metal part. Sphere in middle. (The original Gypsy from KTMA TV23 was made of parts which later became part of Comedy Channel's Cambot, but both robots have been revised since then.)
- Episode 201-512: Rotating alarm light on top. Neck was some sort of hose, a la Gypsy.
- Episodes 513-1013: Two fruit ripening bowls joined to form a sphere. Battery from a pack of Polaroid film. Gypsy tubing.
Cambot presumably survived the destruction of the Satellite of Love in the series finale because we see Mike and the bots living together in an apartment. Something's got to be filming that scene, right? Cambot lives.
References:
http://mst3kinfo.com/mstfaq/bots.html