Fwoosh

Fwoosh is a cloud that will blow Mario and his hat off Tall Tall Mountain in Super Mario 64 and Super Mario 64 DS. Mario can't defeat him but Wario can walk right past him. The mountain wall near him is a portal to a secret slide. Yoshi also has the ability to eat Fwooshes.

He later appears in the Rainbow Ride mission Somewhere Over the Rainbow where if one of the four heroes is shot in the wrong direction, he will fall into the pit after being blown away by Fwoosh.

Although Fwoosh's appearance as an enemy is exclusive to Super Mario 64, a Fwoosh makes a very small cameo in Mario & Luigi: Partners in Time. The cloud appears to blow away the smoke from Thwomp Volcano after the mountain's eruption is put out.

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 him. In Mario Party 3, the player will automatically jump on Fwoosh when jumping at the last block of Awful Tower.

A similar enemy called a Foo appears in New Super Mario Bros. Wii. But Foos only blow clouds so Mario cannot see where he's going, not to blow him away.

It is possible that a Fwoosh is a sub-species of a Lakitu's Cloud.

Trivia

 * In its remake, Fwooshes' face bears a small resemblance to Balloon Boo.