Murmuring Bosk is a mythic Land — Forest card from From the Vault: Realms (V12), collector number 11. Current market price: — (foil $4.41), TCGplayer market prices via Scryfall.
({T}: Add {G}.) As this land enters, you may reveal a Treefolk card from your hand. If you don't, this land enters tapped. {T}: Add {W} or {B}. This land deals 1 damage to you.