After you obtain the Titan’s Mitt, you can travel back to the Light World to find the Cemetery just east of Sanctuary. The grave in the northeast corner of the Cemetery is a little different than the others. The grave is surrounded by extremely heavy stones, but those stones are no match for the Titan’s Mitt. Left the stones, then use the Pegasus Boots to dash into the grave to reveal a hidden cave. Enter the cave to find a chest that contains the Magic Cape.
The Magic Cape makes you invisible. Or, more correctly, the Magic Cape makes you incorporeal. The Magic Cape allows you to pass through enemies and traps–such as Bumpers–of all shapes and sizes, neither being pushed back nor taking damage in the process. It is extremely useful later on when dungeons force you to walk atop beds of nails. Furthermore, enemies will not be able to see you while you are wearing the Magic Cape. However, using the Magic Cape continually drains your Magic Meter while you wear it, so you cannot use it for extended periods of time.