Cape Feathers are a type of feather that transforms Mario and Luigi into Cape Mario and Cape Luigi in Super Mario World. As their caped selves, they can hover in the air and fly, similar to the Super Leaf's effect
Finally, the Cape Feather was also made available as a secret item in Super Mario Advance 4: Super Mario Bros. 3. By scanning in the appropriate card on the e-Reader, the player could upload a Cape Feather into their inventory to use in the game. Cape Mario plays just like he does in Super Mario World, and can even defeat Dry Bones.