Murkfiend Liege is a rare Creature — Horror card from Eventide (EVE), collector number 156. Current market price: $2.28 (foil $28.70), TCGplayer market prices via Scryfall.
Other green creatures you control get +1/+1. Other blue creatures you control get +1/+1. Untap all green and/or blue creatures you control during each other player's untap step.