In "Mario Kart 64", Waluigi is a playable character.

The answer is false because Waluigi does not appear as a playable character in the game Mario Kart 64. Waluigi was introduced as a character in later Mario Kart games in the series, starting with Mario Kart: Double Dash on the Nintendo GameCube. However, in Mario Kart 64, the roster of playable characters includes Mario, Luigi, Peach, Toad, Yoshi, Donkey Kong, Wario, and Bowser.