Become Anonymous is a uncommon Instant card from Assassin's Creed (ACR), collector number 14. Current market price: $0.28 (foil $0.30), TCGplayer market prices via Scryfall.
Exile target nontoken creature you own and the top two cards of your library in a face-down pile, shuffle that pile, then cloak those cards. They enter tapped. (To cloak a card, put it onto the battlefield face down as a 2/2 creature with ward {2}. Turn it face up any time for its mana cost if it's a creature card.)