go read the Cover story about him, it shows that Mermaid and starfish long before the straw hats met her recently. I think it's cool to link the story up with the cover stories. Oda really thinks about these kinds of things. It's what makes him a good writer.
Wonder who that is though in OPs picture. Might be Don, might Kuroro, might be anyone. I can't really remember a whole lot of villains from the manga , my memory stinks.