Fangorn, Tree Shepherd is a rare Legendary Creature — Treefolk card from Tales of Middle-earth Promos (PLTR), collector number 166s. Current market price: — (foil $5.18), TCGplayer market prices via Scryfall.
Treefolk you control have vigilance. Whenever one or more Treefolk you control attack, add twice that much {G}. You don't lose unspent green mana as steps and phases end.