To which fictional work does XXX belong in?
R.O.B.
R.O.B. has appeared as a cameo character in various video games, such as StarTropics, Kirby's Dream Land 3, the Star Fox series, the Mario Kart series, the WarioWare series, the F-Zero series, the Super Smash Bros. series, and Viewtiful Joe; his head appears in Pikmin 2, where it is referred to as ``Remembered Old Buddy''.