Bulb Yoshi

Bulb Yoshi is one of Yoshi's power-ups in the game Super Mario Galaxy 2 along with Dash Yoshi and Blimp Yoshi. Yoshi becomes Bulb Yoshi whenever he eats a Bulb Berry. When this happens, he'll turn yellow, and begin to glow.

While glowing, Yoshi will be surrounded in a circle of light which can reveal passages that aren't normally seen. However, the effects of this power-up are only temporary, so he must eat another nearby Bulb Berry to prolong it. Bulb Yoshi runs out of glow when the music dies down. Bulb Yoshi can also use launch stars and enter pipes.

Trivia

 * The yellow Baby Yoshis of New Super Mario Bros. U has similar functions.