Ghoulcaller's Harvest [Innistrad: Midnight Hunt]

Create X 2/2 black Zombie creature tokens with decayed, where X is half the number of creature cards in your graveyard, rounded up. (A creature with decayed can't block. When it attacks, sacrifice it at end of combat.)
Flashback 3BG (You may cast this card from your graveyard for its flashback cost. Then exile it.)