Pixie Dust is an Item in Captain Hook's Fate deck. It increases the Strength of a Hero in his Realm, making them harder to defeat.
Best used on Peter Pan or a Hero with Taunt, if possible. Failing that, try to put it on a Hero with an ongoing effect, like Wendy.
The following cards in other Villains' Fate decks are functionally the same (ignoring number of copies):