Hour of Eternity is a rare Sorcery card from Hour of Devastation (HOU), collector number 36. Current market price: $0.16 (foil $0.34), TCGplayer market prices via Scryfall.
Exile X target creature cards from your graveyard. For each card exiled this way, create a token that's a copy of that card, except it's a 4/4 black Zombie.