Ozoliath, Apex Amalgamation

Mutate {w}{u}{b}{r}{g}
Haste
Whenever Ozoliath enters the battlefield or attacks, exile target creature card from your hand or graveyard. This card gets "You may mutate this creature from exile. The mutate cost is equal to the casting cost."
Mutate abilities cost {x} less to cast, where X is the number of times this creature has mutated.