Walker of the Grove is a common Creature — Elemental card from Modern Masters (MMA), collector number 173. Current market price: $0.30 (foil $0.25), TCGplayer market prices via Scryfall.
When this creature leaves the battlefield, create a 4/4 green Elemental creature token. Evoke {4}{G} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)