Wendy's Sweet Suite
From the Super Mario Wiki
This level features a boss battle with Wendy. Wendy's sole tactic is moving around, stopping constantly to send out floating red hearts which disintegrate upon touching a solid object other than the ground, and pink hearts with wings that follow Mario around much longer. Mario must jump on Wendy to briefly stun her; he can jump on Wendy again to stun her for a longer period of time. The level consists of ten floors, with anywhere between three to five doors on each floor.