Mordant Dragon is a rare Creature — Dragon card from Duel Decks: Knights vs. Dragons (DDG), collector number 58. Current market price: $0.32, TCGplayer market prices via Scryfall.
Flying {1}{R}: This creature gets +1/+0 until end of turn. Whenever this creature deals combat damage to a player, you may have it deal that much damage to target creature that player controls.