Mello is a young man with chin-length golden-blond hair and blue eyes. His bangs hang down just over his eyebrows, and he stands at about average height. He later gains a large scar, which begins somewhere between his shoulder and waist and extends up to just between his nose and left eye, after initiating an explosion in the Mafia hideout in order to escape being captured. Mello is usually seen wearing dark leather clothes. The manga depicts him wearing a red-colored rosary.