Willow Geist is a rare Creature — Treefolk Spirit card from Innistrad: Midnight Hunt Promos (PMID), collector number 207p. Current market price: $0.41 (foil $0.50), TCGplayer market prices via Scryfall.
Trample Whenever one or more cards leave your graveyard, put a +1/+1 counter on this creature. When this creature dies, you gain life equal to its power.