Leonar Gaogao III, known as Mr. Roarson in English adaptations, is a recurring character in the Shimajiro franchise. He joins the main characters on adventures, frequently commanding specialized transportation and exploration vehicles. His activities involve piloting robotic machines, submarines, and aircraft during journeys to diverse locations. He appears as part of the ensemble in the film *Shimajirō to Kirakira Ōkoku no Ōji-sama*.