Angel's Feather is an item in Kid Icarus and Kid Icarus: Of Myths and Monsters that must be bought at shops in the game. It is activated automatically (and consumed) when Pit hits the bottom of the screen, allowing him to fly for a short amount of time in an attempt to recover his footing. It is a near-necessity in Skyworld but also useful in the Overworld when attempting to traverse the large seas. Once Pit has equipped the Wings of Pegasus (one of the Three Sacred Treasures), Angel's Feathers become useless and can never be used again.
Merchants sell this for 390 Hearts, unless Pit's bargained them down, in which case he'll get a mighty discount to 150; failure, though, raises the price to 630. A Black Marketeer sells Feathers for 450.
This item is only found while traveling; it's not in stores. It grants Pit the temporary ability of full flight, but only lasts for several seconds, much like a primitive version of the Power of Flight.
This item, renamed "Wings of Icarus," is Pit's Up Special. The wings allow him to fly upwards, giving his wings a blue glow, for a moderate period of time before becoming useless. It is considered one of the best recovery abilities, mirroring its importance in the first Kid Icarus.