Blanchwood Prowler is a common Creature — Elemental card from The Brothers' War (BRO), collector number 172. Current market price: $0.26 (foil $0.22), TCGplayer market prices via Scryfall.
When this creature enters, mill three cards. You may put a land card from among the cards milled this way into your hand. If you don't, put a +1/+1 counter on this creature. (To mill a card, put the top card of your library into your graveyard.)