Slumbering Walker is a rare Creature — Giant Warrior card from Lorwyn Eclipsed Promos (PECL), collector number 35p. Current market price: $0.60 (foil $0.89), TCGplayer market prices via Scryfall.
This creature enters with two -1/-1 counters on it. At the beginning of your end step, you may remove a counter from this creature. When you do, return target creature card with power 2 or less from your graveyard to the battlefield.