Barrel Train

The Barrel Train is Diddy Kong's lightweight kart in Mario Kart: Double Dash!!. It is unlocked by completing the Star Cup in 150cc. Its nitrous comes from the horn, which makes the sound of a train whistle when speed boosting. Like any steam engine, the Barrel Train's exhaust pipe is a smokestack.

The Barrel Train is the heaviest lightweight kart in the game; its weight is tied with the medium karts Red Fire and Heart Coach, and is greater than the Green Fire and Bloom Coach, which it can push around as a result. It is tied with the Bullet Blaster as the fastest light kart, however it also has the lowest acceleration of its weight class.

A train that resembles the Barrel Train can be seen buried in Gritzy Desert during the (past) events of Mario & Luigi: Partners in Time. Another train named the "Barrel Train" appears in Mario Party 8; unlike Diddy's kart, this is a full-size locomotive that runs on tracks. Later, in Super Smash Bros. Brawl, Diddy's Barrel Train appears as a sticker that raises a player's attack by nineteen.

Trivia

 * Since this is a lightweight vehicle, Donkey Kong (Diddy Kong's partner) cannot ride in it