Mustache Pirates

Featured in the sixth One Piece movie, the Mustache Pirates were a crew led by Brief. Their flag bore a skull sporting a toothbrush mustache and a hat, echoing the look of the whole crew, since each member wore the very same mustache, a uniformity the series rarely shows outside this band and the Caribou Pirates. Beyond Brief himself, the rest of the crew only ever appear in a single photograph, and the captain also kept a pet goat.

As captain, Brief was almost certainly the strongest of the lot, though the rest of the crew's abilities were never witnessed. Their fate was sealed when they reached Omatsuri Island and the Red Arrows Pirates, by way of Lily Carnation, easily killed off everyone but Brief. The surviving captain set his sights on toppling Omatsuri and tried to recruit Luffy to the cause.

Brief stands as the only named member. He shadowed the Straw Hats after they landed, then offered Luffy a spot in his crew, which Luffy declined out of loyalty to his own. Brief later saved Luffy from Omatsuri and, after the two teamed up with Papa and the Tearoom Pirates to bring the villain down, parted as friends. By the film's close he vowed to remember Luffy and to seek out a new crew, inspired by him.