One Piece: Monster of the Straw Hat Pirates

Within the Grand Line there is a 4th kind of Zoan Devil Fruit: the Kaiju-Zoan. Granting the eater the powers of creatures of great power, they can also bring about terrible destruction. Gian is one such person, and though he only wants to help his newfound captain attain his dream of becoming Pirate King, he'll soon find that his power means much more than he originally believed.