The Rosy Life Riders, formerly called the Flying Fish Riders (トビウオライダーズ), were a kidnapping gang from around Sabaody Archipelago. The members each ride on a flying fish, hence their gang’s name. Their leader was Duval. With the handles on their flying fish and the way they dress, they resemble a biker gang. Since Duval’s face alteration, however, the gang was reformed into the “Rosy Life Riders”, and their purpose changed.

(Source: One Piece Wiki)