Dragon Lords
From Wookieepedia, the Star Wars wiki.
A group of natives on the planet Drexel II had been exiled from their positions of technicians to the Master Machinesmith because they were disgruntled by the oppressive Masters. Stranded at sea, they learned the ability to command and control the native Sea-dragons, using ultrasonic devices to control them and use them as mounts. This ability to control and command was primarily used by the Dragon Lords as a ruse, for they actually had discovered that the sea-dragons were intelligent creatures who welcomed the exiles. With the help of Han Solo and Luke Skywalker, they eventually overthrew Governor Quarg and reclaimed their world.
