Ozma

In an endless desert without a speck of greenery, Sam Coyne rides a motor bike, looking for something, when he sees a girl being chased by seemingly-hostile ships. Sam saves the girl, whose name is Maya, who might actually not be a criminal on the run, but royalty... Before returning to the safety of his group's base, he sees a giant monster rise out of the sand. It's the monster who is his brother's enemy... The sand whale Ozma.

Synopsis from Anime News Network