Haze Dragon

Empty {r} (You may cast this card for its empty cost. If you do, exile it as it resolves. During your precombat main phase, if an opponent cast no spells last turn, you may cast the exiled card without paying its mana cost. Empty only as a sorcery.)
When Haze Dragon enters the battlefield it deals
2 damage to target creature.
Some say magma dragons hide some of the best kept secrets of the multiverse.