“Thunder Lord” McGuy is an infamous New World pirate who allied himself with Whitebeard. He has a long face with a big nose, wavy hair, and a black mustache shaped like a lightning bolt.

McGuy has managed to make himself an infamous reputation in the New World, and has managed to ally himself with Whitebeard.

He and his crew are first seen, along with a fleet of 42 other infamous pirate crews, allied with the Whitebeard Pirates, attacking Marineford to save Portgas D. Ace from his execution.

(Source: One Piece Wikia)