Marwyn, the Nurturer is a rare Legendary Creature — Elf Druid card from Kaldheim Commander (KHC), collector number 68. Current market price: $5.99, TCGplayer market prices via Scryfall.
Whenever another Elf you control enters, put a +1/+1 counter on Marwyn. {T}: Add an amount of {G} equal to Marwyn's power.