Two of the racers is the racing segment are the infamous Mario and Luigi of Super Mario Bros. fame. Due to Mario's popularity among gamers, Nintendo made games other than the regular Mario games to make more profit, such as Super Mario Kart.
The game, originally released on the Super Nintendo, became one of the best selling games in Nintendo's history for the Super Nintendo. As a result, Nintendo has made a "Mario Kart" game for every other console after the Super Nintendo, including (but not limited to):
Mario Kart 64* (Nintendo 64)
Mario Kart Super Circuit (Game Boy Advance)
Mario Kart: Double Dash!! (Gamecube)
Mario Kart DS (Nintendo DS)
*The blue tortoise shell (Spiny's Shell) would not be included until Mario Kart 64, and the only difference between the version in the game and the version in the sketch is that the game's shell has spikes on it.