Dracule "Hawk-Eyes" Mihawk is a member of the Shichibukai and the current holder of the title, "Greatest Swordsman in the World".
He is possibly one of the most serious characters in One Piece; very little seems to surprise him, he rarely smiles, and he has only been seen laughing once in the series so far. He takes the revelation about Luffy being Dragon's son in stride, despite the surprise of those around him. He never unnecessarily reveals emotions on the battlefield, even when he's trumped.
Mihawk's strength is so great that Don Krieg accuses him of having the power of a Devil Fruit; however, in the Databooks, his abilities appear to be simply brute skill and power. Dracule Mihawk is the only Shichibukai whose strength is based totally on natural human skill, being completely human (Jinbe being a Fishman and Bartholomew Kuma being a Pacifista), and possessing no Devil Fruit powers.