Bouncy Cloud

Bouncy Clouds are cloud platforms that appear in New Super Mario Bros. Wii, New Super Mario Bros. U and New Super Luigi U. Anything that lands on them bounces very high, including enemies. Their appearance is reminiscent of Cloud Blocks, as both are white fluffy cloud featuring a smiling face in the middle.

New Super Mario Bros. Wii
In New Super Mario Bros. Wii, they only appear in World 2-6 and World 9-8.

New Super Mario Bros. U
In New Super Mario Bros. U, they appear in two levels, several of them can be found in the level Bouncy Cloud Boomerangs, and a single one is found in the final level of Superstar Road, Follow That Shell!.

New Super Luigi U
In New Super Luigi U, they are also found in two levels, Above the Bouncy Clouds, and Flying Squirrel Ovation.