The Nameless King

Mutate {3}{r/g}{u}{u}(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.)
Flying, trample
Whenever this creature mutates, exile cards from
the top of your library until you exile a nonland permanent card. Put that card onto the
battlefield or into your hand.