Marco is a tall, lean, muscular man with a perpetually sleepy look on his face and a light stubble around his chin. His short blond hair sticks up from the top of his head like a crown, and he wears an open purple jacket over a light blue sash adorned with an elaborate golden-yellow belt. Dark gray knee-length pants and black sandals complete his outfit, with a straw decoration on his left leg. Despite his relaxed demeanor, Marco is fiercely loyal to his captain, Whitebeard, and remains calm and level-headed even in dire situations. However, any threat to Whitebeard can shatter that composure, revealing a protective and emotional side. He is also highly perceptive, able to sense powerful presences like Shanks' Supreme King Haki before anyone else.