Gusty

Gusties are long, happy ghost-like creatures in Super Mario World 2: Yoshi's Island, Yoshi Touch and Go, and Yoshi's Island DS. They always travel in huge packs, giving Yoshis extra eggs, and making stepping stones to reach high areas.

They appear in levels where the terrain is bumpy and uneven, and are often a nuisance, since they can spawn endlessly. Also, they can cause Yoshi to lose the baby that he's carrying, just by colliding into him.