Shachi is one of the members of the Heart Pirates. Not much is known about him yet. Like Penguin, he likes women, seems to be a pleasant man, and is loyal to his captain, Law. As a teenager, he was a bully who was prone to mocking people and picking fights, and seemed to respect strength, as he joined up with Law after the latter beat up him and Penguin.
(Source: One Piece Wikia)