Meowth's Party (lost Nintendo GameCube tech demo; 2000)
Meowth's Party is a tech demo/rumored game for the Nintendo Gamecube. The song and video featured Meowth singing and dancing for a group of Pokemon while on a stage. Meowth's Party was originally thought to be a GameCube game, as a music video (not the same as the ending animation) featuring the song with GameCube graphics was shown at the Nintendo Space World Convention in 2000 before the console's launch to demonstrate the systems graphical capabilities. However, the video was later included on another Gamecube game, Pokemon Channel, and was not made into its own game.
Link to Youtube recording of Nintendo Space World 2000 recording: