Identity Thief is a rare Creature — Shapeshifter card from Eldritch Moon Promos (PEMN), collector number 64s. Current market price: — (foil $0.43), TCGplayer market prices via Scryfall.
Whenever this creature attacks, you may exile another target nontoken creature. If you do, this creature becomes a copy of that creature until end of turn. Return the exiled card to the battlefield under its owner's control at the beginning of the next end step.