Draconic Roar is a uncommon Instant card from Dragons of Tarkir (DTK), collector number 134. Current market price: $0.12 (foil $0.62), TCGplayer market prices via Scryfall.
As an additional cost to cast this spell, you may reveal a Dragon card from your hand. Draconic Roar deals 3 damage to target creature. If you revealed a Dragon card or controlled a Dragon as you cast this spell, Draconic Roar deals 3 damage to that creature's controller.