Mii

Miis are characters users can create on a Wii or 3DS via the Mii Channel. They also appear in two different outfits as unlockable drivers in Mario Kart Wii. The first outfit is unlocked by winning the 100cc Special Cup, and the second outfit is unlocked by unlocking all thirty two Expert Staff Ghosts in Time Trials mode. They also appear as playable characters in Mario Super Sluggers and Mario Sports Mix.

Mario Party 8
Miis were playable in the recent game, Mario Party 8. However, the Mii is not playable in the main game and instead can only be played in the minigames in the Extra Zone.

Mario Kart Wii
Miis are compatible with Mario Kart Wii. They can be any size, depending on their height. This makes them the most versatile characters. Miis must be unlocked. The Mii's voice also varies depending on the color their shirt is. Also, Miis from your Mii plaza sometimes appear in the crowd, or on statues in some tracks. Miis have two outfits: Mii Outfit A and Mii Outfit B.

Mario Kart 7
Miis will also become playable in Mario Kart 7 for the 3DS.