Summoning Trap [Zendikar]

Set: Zendikar Type: Instant — Trap Rare Cost: {4}{G}{G} 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.