Corpse Cobble is a uncommon Instant card from Innistrad: Midnight Hunt (MID), collector number 214. Current market price: $0.29 (foil $0.28), TCGplayer market prices via Scryfall.
As an additional cost to cast this spell, sacrifice any number of creatures. Create an X/X blue and black Zombie creature token with menace, where X is the total power of the sacrificed creatures. Flashback {3}{U}{B} (You may cast this card from your graveyard for its flashback cost and any additional costs. Then exile it.)