Wolfwillow Haven is a uncommon Enchantment — Aura card from Theros Beyond Death (THB), collector number 357. Current market price: $0.61 (foil $0.81), TCGplayer market prices via Scryfall.
Enchant land Whenever enchanted land is tapped for mana, its controller adds an additional {G}. {4}{G}, Sacrifice this Aura: Create a 2/2 green Wolf creature token. Activate only during your turn.