Balloon Baby Yoshi

Balloon Baby Yoshi is a magenta Baby Yoshi appearing in New Super Mario Bros. U. It allows the player to reach higher places by inflating like a balloon when the player shakes the or presses the  button on the. Balloon Baby Yoshis can inflate to a maximum of seven times, and will deflate afterwards or when the player lands. Other players can grab on to the player with the Baby Yoshi, presumably the same way players can lift one another. Balloon Baby Yoshi also adds a chorus to the current music, one he himself creates.

Only one appears in Super Mario-Kun, where the Baby Yoshi bites Mario with sharp/properly brushed fangs, causing blood.

Trivia

 * Balloon Baby Yoshi is very similar to Blimp Yoshi from Super Mario Galaxy 2, except that the Blimp Yoshi has a time limit and starts when a power up is collected while already carrying a Yoshi, but Balloon Baby Yoshi has an input limit and is a certain subset of Yoshis.