Chimaeric Nightstalker

Mutate {b}{r}{g} (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.
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Deathtouch, Menace, Protection from White
Whenever this creature mutates, you can exile 1 card from your Graveyard. if you do, put a +1/+1 counter on this card.