In the game, this foe can attack Mario or Luigi with its tail by swaying it. It first floats in midair and then lands down and sways its tail. The distance varies though. As they are larger, their tail swings more far. Because their size has to fit inside the 3DS screen in this game, their size had been cut down to be a little more tall than a regular Goomba or a Tail Goomba.
Their appearance in the game first is in the first level where only a single one of these foes appear. Many more appear in World 5-5.