Savage Ventmaw is a uncommon Creature — Dragon card from Battlebond (BBD), collector number 229. Current market price: $1.15 (foil $11.84), TCGplayer market prices via Scryfall.
Flying Whenever this creature attacks, add {R}{R}{R}{G}{G}{G}. Until end of turn, you don't lose this mana as steps and phases end.