User avatars for Nintendo's Wii, 3DS, and Wii U video game systems. Typically super deformed (chibi), sometimes without legs or arms (though inclusive of hands).
Numerous Nintendo games, such as Mario Kart (since Mario Kart Wii) and Super Smash Bros. allow players to use their Miis as playable characters.
Nikki is an original Mii character for Swapnote.
In the Super Smash Bros. series, the generic Miis used to represent the Fighter, Gunner, and Swordfighter types are shown to be based off the default Miis Guest C, Guest F, and Guest B.