Miis are player-created avatars devised by Nintendo. Created at the system level, an individual Mii can appear in any game that supports their use. Miis were first introduced with the Wii, and the first game to support them was Wii Sports. Depending on the game, Miis may appear as the player's character in a game, appear in the background, or perhaps appear in portrait form to serve as an iconic representation of the player.
When Miis were first introduced, the only way to create them was through the Mii Channel on the Wii console. However, later Nintendo hardware including the 3DS and Wii U offer the ability to create Miis based on a player's likeness through the use of a camera. Mii creation offers a variety of customization options, including gender, skin tone, hair style and hair and eye color, the shapes of facial features, height, and build. Each Mii may also be assigned a color and designated as a "favorite".