Bulb Berry

The Bulb Berry is a type of berry, and one of three power-up fruits for Yoshi in Super Mario Galaxy 2 along with the Dash Pepper and the Blimp Fruit. The berry appears as an inverted glowing light bulb with a yellow stem on it, making it similar to a pear, eggplant, or papaya. The Bulb Berry gives Yoshi the ability to light up hidden paths, similar to the bouncing matter in Matter Splatter Galaxy from the first game; this power-up is known as Bulb Yoshi. It has a time limit, represented in the form of a tone, much like the Fire Flower. It first appears in the Haunty Halls Galaxy, in the mission A Glimmer of Bulb Berry. The next and last galaxy it appears in is the Sweet Mystery Galaxy. Here, almost the whole galaxy requires the use of the Bulb Berry to light up platforms.

Super Mario Galaxy 2

 * North American website bio: "When Yoshi eats this berry he becomes Bulb Yoshi, and our heroes can see hidden platforms thanks to the mysterious golden light emitted from his body. Those platforms may not last long though!"

Trivia

 * The Bulb Berry is missing from the back of the game's box, where all the new power-ups for Yoshi and Mario are mentioned.