Ikoria: Lair of Behemoths

Chittering Harvester | Creature | Nightmare | Mutate {4}{B} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.) Whenever this creature mutates, each opponent sacrifices a creature. | Grzegorz Rutkowski

Back for More | Instant | | Return target creature card from your graveyard to the battlefield. When you do, it fights up to one target creature you don't control. (Each deals damage equal to its power to the other.) | Daarken