Summon the Pack is a mythic Sorcery card from The List (Unfinity Foil Edition) (ULST), collector number 25. Current market price: — (foil $0.55), TCGplayer market prices via Scryfall.
Open a sealed Magic booster pack, reveal the cards, and put all creature cards revealed this way onto the battlefield under your control. They're Zombies in addition to their other types. (Remove those cards from your deck before beginning a new game.)