text: If you choose to cast a card as Colossal Dreadmaw, while on the stack, treat that spell as though it were Colossal Dreadmaw (including the mana cost to cast it). After it resolves, treat the permanent it becomes as though it were Colossal Dreadmaw for as long as it remains on the battlefield. Once it leaves the battlefield, the card goes back to its normal self.