Auspicious Starrix
{4}{G}
Creature -- Elk Beast
6/6
Mutate {5}{G} (If you cast ~this~ 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.)
Whenever ~this~ mutates, exile cards from the top of your library until you exile X permanent cards, where X is the number of times ~this~ has mutated. Put those permanent cards onto the battlefield.