R.O.B.

Robotic Operating Buddy, or R.O.B. for short (known in Japan as Family Computer Robot, or Robot for short), is some sort of old robotic toy created by Professor Hector and his assistant Professor Vector. He functions by translating flashes of information on the television screen into physical actions to assist players in compatible games. His functionality seems pretty limited at first glance, being able to use gyros and stack blocks, but he's versatile enough to have shown up in several unexpected roles, acting as a treasure, gift, furniture item, fighter, kart racer, etc.