Goblin Dark-Dwellers (Oath of the Gatewatch Promos)

Creature — Goblin - Menace (This creature can't be blocked except by two or more creatures.)
When this creature enters, you may cast target instant or sorcery card with mana value 3 or less from your graveyard without paying its mana cost. If that spell would be put into your graveyard, exile it instead.