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. It resembles the train from Kalimari Desert as well as the K64 from Paper Mario.

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

Being a lightweight kart, Donkey Kong (Diddy's default partner) can't ride on the Barrel Train. Therefore, Diddy needs to be paired with another lightweight to use this kart.

Although it has a 4 star speed stat, the Barrel Train is surprisingly faster than most 4 star speed karts, including the Koopa King, which has a 5 star speed stat, and that's primarily due to the fact that its traction is very weak (the Barrel Train's speed hardly drops at all when hit by a Thunderbolt). This kart is also a popular choice for getting good times in the Time Trials game mode.

This kart is also one of the four karts to have stats "out of the ordinary" for its weight class, with the others being the Green Fire, the Boo Pipes, and the Turbo Birdo.

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 leg attack by nineteen.