Kunoros, Hound of Athreos is a rare Legendary Creature — Dog card from Theros Beyond Death Promos (PTHB), collector number 222p. Current market price: $0.67 (foil $0.51), TCGplayer market prices via Scryfall.
Vigilance, menace, lifelink Creature cards in graveyards can't enter the battlefield. Players can't cast spells from graveyards.