R.O.B. (Robotic Operating Buddy)

I remember seeing these as a kid but had no idea what it did ? R.O.B. (Robotic Operating Buddy) is a robot that could substitute for a second player in the Nintendo Entertainment System games Stack-Up and Gyromite. The short-lived accessory did not prove to be popular, leading Nintendo to cancel it. In the following years R.O.B. would remain alive in Nintendo's video games, however, appearing as a playable character in Mario Kart DS and Super Smash Bros. Brawl and making several cameo appearances in titles such as StarTropics, the WarioWare games, Pikmin 2 and more.