Long River Lurker is a uncommon Creature — Frog Scout card from Bloomburrow (BLB), collector number 57. Current market price: $0.27 (foil $0.37), TCGplayer market prices via Scryfall.
Ward {1} Other Frogs you control have ward {1}. When this creature enters, target creature you control can't be blocked this turn. Whenever that creature deals combat damage this turn, you may exile it. If you do, return it to the battlefield under its owner's control.