Huntmaster Liger — Ikoria: Lair of Behemoths #16

Mutate (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, other creatures you control get +X/+X until end of turn, where X is the number of times this creature has mutated.