Baby Luigi is a character in Nintendo's Mario series, similar to Baby Mario. He is believed to be Luigi as an infant, although he has appeared in Mario Kart: Double Dash!! and various other Mario sport games alongside his "older self". It is generally accepted that these games do not have storylines and merely offer extra playable characters for greater variety. Baby Luigi first appeared in Super Mario World 2: Yoshi's Island where he got kidnapped by Kamek, only to be rescued by his brother Mario and Yoshi later on.
Baby Luigi more recently appeared in Yoshi Touch & Go, where Yoshi must rescue him by hitting the Toadies carrying him with eggs. In the multiplayer mode, the second player's Yoshi will be carrying Baby Luigi instead of Baby Mario.