Summoning Trap is a rare Instant — Trap card from Zendikar (ZEN), collector number 184. Current market price: $0.37 (foil $2.09), TCGplayer market prices via Scryfall.
If a creature spell you cast this turn was countered by a spell or ability an opponent controlled, you may pay {0} rather than pay this spell's mana cost. Look at the top seven cards of your library. You may put a creature card from among them onto the battlefield. Put the rest on the bottom of your library in any order.