Vadrok, Apex of Thunder (Showcase)

Mutate [1][W/U][R][R] (If you cast this spell for its mutate cost, put it over/under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Flying, first strike

Whenever this creature mutates, you may cast target noncreature card with converted mana cost 3/less from your graveyard without paying its mana cost.