Big Donut is one of the four battle stages in Mario Kart 64. The stage is shape in as a large doughnut and in the middle of the stage has a large hole filled with lava. If a player falls into the lava, they lose a balloon and Lakitu will recuse them.
On this stage, there will be four block towers that are located around the stage and they are used to evade opposing racers and any items being thrown at the player. Big Donut will also slightly slope inwards toward the lava.
It would return in Mario Kart 7 as one of the retro battle courses in the game. It would have several new elements like jumping ramps so that the players could glide over the pool of lava. The Koopa Clown Car would also be seen floating in the center of the course with air currents so the glider can glide higher. Lava would occasionally rise from the pool of lava to attempt to hit the player while they glide.