Baby Luigi is the baby form/infant counterpart of Luigi. He wears green clothes, much like Luigi. He is Mario's brother Luigi in baby form. He was first introduced alongside Baby Mario in Super Mario World 2: Yoshi's Island, in which the aim of the game was to rescue him from Baby Bowser.
Baby Luigi appeared in this game alongside Mario, Luigi, and Baby Mario in which combined with Luigi could achieve combo attacks. He always seemed to find it enjoyable (or hilarious) to see his older self get conked on the head.
Baby Luigi first appeared as a playable character in Mario Kart: Double Dash!! as the partner of Baby Mario. His Car is the Green Pram, which is a lightweight car and his special item is the Chain Chomp He was absent from Mario Kart DS, but returns in Mario Kart Wii. Adding to his stroller car, he also drives a motorbike.
He is unlocked by getting 8 expert staff ghosts on time trials.He returns as a racer in Mario Kart 8 and Mario Kart 8 Deluxe.