Howling Moon is a rare Enchantment card from Innistrad: Double Feature (DBL), collector number 471. Current market price: $3.51 (foil $6.69), TCGplayer market prices via Scryfall.
At the beginning of combat on your turn, target Wolf or Werewolf you control gets +2/+2 until end of turn. Whenever an opponent casts their second spell each turn, create a 2/2 green Wolf creature token.