From the Super Mario Wiki
The Special Cup is the final cup of each game in the Mario Kart series (except Mario Kart DS, Mario Kart Wii, and Mario Kart 7, because there are Retro Cups after the normals, and there, the Lightning Cup is the last one). In Super Mario Kart, the player may unlock it by winning all three cups in 100cc (though it will be unavailable for the 50cc class); in Mario Kart: Super Circuit it is available by winning the four previous cups, each by class; in Mario Kart: Double Dash!!, it appears after the player finished first in the Star Cup in 100cc; from Mario Kart DS onwards, it is unlocked once the player claims a gold trophy in the Star Cup. Special Cup consists of long, difficult courses. It normally has a Bowser's Castle course in all games except the first two games and always ends with Rainbow Road. Bowser's Castle is the penultimate course before Rainbow Road. The emblem of the Special Cup is currently a crown (seen to the right), although in Mario Kart 64 and Mario Kart Super Circuit it is represented by the letter "S", the initial of "special." In Super Mario Kart it is a combination of the three emblems used for the Mushroom Cup, Flower Cup, and Star Cup.
List of Courses
Mario Tennis Open
The Special Cup reappears in Mario Tennis Open. In this game it is called the Champions Cup. It is the last cup in World Open tournament series. Players can unlock this cup when they clear the Banana Cup. When players clear this cup, their character earns a star rank, which boosts their stats and grants them access to the Star Open tournament series. The court played here is the grass, clay and hard courts in Mario Stadium.
Names in other languages