Bowser Jr. Cup
From the Super Mario Wiki, the Mario encyclopedia
The Bowser Jr. Cup is a cup that appears in the Mario Kart series. It first appears in Mario Kart Arcade GP DX, where it is the fourth out of the six cups in the game. It also appears to be a follow-up to the fifth cup, the Bowser Cup. Its courses are based off of the cloud worlds from the New Super Mario Bros. games.
Mario Kart Arcade GP DX
Mario Kart Tour