Baby Mario

Baby Mario is Mario's baby self who first appeared in Super Mario World 2: Yoshi's Island. In this game, the Stork is on his way to deliver Baby Mario and Baby Luigi to the their parents in the Mushroom Kingdom. However, on the way, Kamek, an evil Magikoopa, kidnaps Baby Luigi and the Stork. Baby Mario falls into Yoshi's Island and lands on the back of a green Yoshi. Kamek has predicted that the Mario brothers will cause problems for the Koopas in the future, and as such he attempts to kidnap the babies. The Yoshi brings Baby Mario to the other Yoshies, and they decide to help Baby Mario rescue Baby Luigi from Kamek and Baby Bowser.

Baby Mario is a playable character in most of the Mario sports titles, such as Mario Golf Mario Tennis Mario Kart: Double Dash!!! and Mario Superstar Baseball. How Baby Mario can exist in the same time period as Mario remains a mystery. This was explored to a certain extent in Mario & Luigi: Partners in Time, although Nintendo has yet to link the game to the sports titles.

Baby Mario, and his brother Baby Luigi, star alongside adult Mario and Luigi in Mario & Luigi: Partners in Time for the Nintendo DS. They ride on the adults' shoulders, and a baby takes over when one of the adults runs out of HP.

He'll also be playable in the new Yoshi's Island 2, the only abilities he has is an increase in Yoshi's speed and possibly other skills. He also lets them groud pound enemies. Basically he's untouched from the oringinal Yoshi's Island.

Mario Superstar Baseball Bio
"The elder of the baby Mario Brothers. After arriving in a stork-related calamity, he and Yoshi rescued his little bro. Though he's supposed to be Mario in his youth, you can play as both of them at the same time for some reason. He has excellent foot speed but lacks power do to his diminutive size."