this is for GP and HD. SCR GP/HD aka Robot #1 and Robot #2 debuted in the racing game Sonic Riders: Zero Gravity, the sequel to the original Sonic Riders. Upholding the Sega tradition of "wasting of character slots" that they demonstrated with the egg pawn characters in the first Sonic Rider, these guys were basically common enemies made playable. I mean, who needs cool characters like the Chaotix or Metal Sonic when we can play as badniks? I'm guessing their names stand for "Some Crappy Robot Grand Prix/High Definition" but I really don't care. At least they're cooler than egg pawns, and their overall design is at least creative. And they can turn into donuts. Everyone likes donuts.