The Great Henge is a mythic Legendary Artifact card from Throne of Eldraine Promos (PELD), collector number 161p. Current market price: $67.83 (foil $69.40), TCGplayer market prices via Scryfall.
This spell costs {X} less to cast, where X is the greatest power among creatures you control. {T}: Add {G}{G}. You gain 2 life. Whenever a nontoken creature you control enters, put a +1/+1 counter on it and draw a card.