Baby Mario is a baby version of Mario, who started appearing in Yoshi games. His debut was in Super Mario World 2:Yoshi's Island. In this game, him and Baby Luigi are being delivered by the stork. On their way though, they are kidnapped by Kamek, an evil Magikoopa. Then, Baby Mario falls and lands on Yoshi's back on Yoshi's Island. Yoshi then takes Baby Mario back to the other Yoshis, and they decide to help him rescue Baby Luigi. Meanwhile, Kamek sees that in the future, Baby Mario (Mario ) will cause trouble for the koopas, so he goes after him, and from there the adventure begins. Now, Baby Mario still appears in other Yoshi games, and in the spin-off Mario sports games.
- Baby Mario's hat looks big on him this may mean that this is the same hat he wears now meaning that he kept the hat all his life
- Baby Mario and Baby Luigi make cameo appearances in the introduction of Mario power tennis. In the audience, they cheer when Mario and Luigi defeat Wario and Waluigi in doubles tennis.
- In Super Smash Bros. Brawl, Baby Mario's trophy states that he does not wear overalls. Baby Mario actually does wear overalls, although Nintendo may have been focusing on the Yoshi series.