My opponent cast a Languish while I had a Scavenging Ooze on board and 3 open green mana. I activated it, exiling a creature from my graveyard, and after the ability resolved, it auto pass priority, resolving the Languish. There were plenty more cards in graveyard, and had I been able to activate it again, I could have exiled another creature in my graveyard and saved the Ooze.