Pouncing Shoreshark
From Ikoria: Lair of Behemoths set
Pouncing Shoreshark
Creature — Shark Beast
4/3
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.)
Flash
Whenever this creature mutates, you may return target creature an opponent controls to its owner's hand.