Boo Pipes

The Boo Pipes are King Boo's unlockable kart in Mario Kart: Double Dash!!. They are a gray version of Petey Piranha's Piranha Pipes, and can be unlocked by completing the Special Cup in Mirror Mode.

Unlike most heavyweight karts, the Boo Pipes are unique for having traits similar to that of a lightweight kart; low top speed and high acceleration. But unlike the lightweight karts, this kart is heavy enough to rival the weight of the Koopa King and Piranha Pipes. These traits make the Boo Pipes a very effective kart to use in GP races. However, the kart isn't very useful in Time Trials, due to its low top speed.

The Boo Pipes have one of the best acceleration stats in the game, being tied alongside the Rattle Buggy and Koopa Dasher; they're also tied with those two karts in terms of top speed. Lastly, when compared to all the other heavyweight karts, the Boo Pipes lose the least amount of speed whenever they go off-road.

The Boo Pipes are one of the four "out of the ordinary" karts for their weight class, with the others being the Green Fire, the Turbo Birdo, and the Barrel Train.

Trivia

 * In terms of stats, the Boo Pipes may have been designed to be a heavier version of the Heart Coach, a medium kart with near-identical stats (other than weight) and even the same engine sound.
 * The Boo Pipes, Piranha Pipes, Heart Coach, and Bloom Coach share the same engine sound.
 * The Boo Pipes' horn sound is highly similar to the Piranha Pipes' horn sound, except for that it's lower-pitched.

Tubo Boo Buu-Huu-Röhre