Aid from the Cowl is a rare Enchantment card from Aether Revolt (AER), collector number 105. Current market price: $0.27 (foil $0.68), TCGplayer market prices via Scryfall.
Revolt — At the beginning of your end step, if a permanent left the battlefield under your control this turn, reveal the top card of your library. If it's a permanent card, you may put it onto the battlefield. Otherwise, you may put it on the bottom of your library.