Super Mario Galaxy 2
Game Wiki Sections
Yoshi's Special Abilities
Yoshi has a few special abilities that can be attained by eating fruits throughout the game. These fruits only appear in some levels.
When Yoshi eats a Dash Pepper, he will get a big boost of speed for a short time. This enables Yoshi to run on water or run up walls. However, Yoshi is very hard to control with the Dash Pepper, so be careful that you don't lose control of Yoshi and fall off of a planet.
The Blimp Fruit fills Yoshi with air and enables him to fly much higher than he can with his jump. When Yoshi is in mid-flight, use the air meter that appears next to Yoshi's head to see how much longer you have to fly. Make sure that you do not run into any enemies while using the Blimp Fruit, or else Yoshi will pop and then fall down.
The Bulb Berry enables Yoshi to see invisible platforms and objects that you can not normally see. However, Yoshi must keep collecting Bulb Berries while he is out in open space or else he will fall.