Shifting Shadow is a rare Enchantment — Aura card from Treasure Chest (PZ2), collector number 65703.
Enchant creature Enchanted creature has haste and "At the beginning of your upkeep, destroy this creature. Reveal cards from the top of your library until you reveal a creature card. Put that card onto the battlefield and attach Shifting Shadow to it, then put all other cards revealed this way on the bottom of your library in a random order."