Bubble Baby Yoshi
From the Super Mario Wiki
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Bubble Baby Yoshi is a blue-colored Baby Yoshi appearing in New Super Mario Bros. U. It can blow out Bubbles if the player shakes or on when the character is grabbing one. These Bubbles are able to instantly defeat most enemies, turning them into three Coins (six coins from certain larger enemies), a Super Mushroom, a Fire Flower, Ice Flower, Super Acorn, or 1-Up Mushroom, which the player can collect. What any given enemy will turn into boils down to chance, though Coins are by far the most likely.
Players also have the ability to bounce on the bubbles to reach higher places. Bubble Baby Yoshi also adds a chorus to the current music, one he himself creates.
Bubble Baby Yoshis can be seen on the world map, in Frosted Glacier and Rock-Candy Mines and can be met and taken to any other course. A Bubble Baby Yoshi appears in a challenge in Challenge Mode, where Mini Mario must use his bubbles to reach the top of the stage. Also, they are found in some Toad Houses alongside other Baby Yoshis.
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