From the Super Mario Wiki
A Fwoosh is a cloud enemy that first appeared in Super Mario 64. It attacks by blowing strong gusts of wind in order to push characters off high altitudes.
Super Mario 64
In Super Mario 64 and Super Mario 64 DS, a single Fwoosh will blow Mario and his hat off Tall Tall Mountain. Mario can't defeat it but Wario can walk right past it. The mountain wall after it is a portal to a secret slide. Yoshi also has the ability to eat Fwooshes.
Mario & Luigi: Partners in Time
Mario Party series
Fwoosh has also made many appearances in the Mario Party series. It's proven there that one can stand on a Fwoosh, because in Mario Party, the player can, in Mini-Game Island, warp from world to world by hopping on it. Fwoosh will also bring the player back to start in Mario's Rainbow Castle, again by stepping on it. In Mario Party 3, the player will automatically jump on Fwoosh when jumping at the last block of Awful Tower. The players ride Fwoosh in the introduction of Parasol Plummet.
A Fwoosh appears while Mario, Yoshi, and the Bob-omb Buddy ride on a magic carpet in Rainbow Ride in volume 16 of the Super Mario-Kun. It blows Mario's hat away, where it lands on a big Boo.