Ben 10 Hero of Heros

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.)
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.
"It's hero time!" —Ben Tennyson