Kilnmouth Dragon is a rare Creature — Dragon card from Duel Decks: Knights vs. Dragons (DDG), collector number 59. Current market price: $0.92, TCGplayer market prices via Scryfall.
Amplify 3 (As this creature enters, put three +1/+1 counters on it for each Dragon card you reveal in your hand.) Flying {T}: This creature deals damage equal to the number of +1/+1 counters on it to any target.