From publisher blurb:
Masters of Dune and Wave!
It is said that the desert and the ocean have much in common, with the rolling dunes of sand often being compared to the rolling waves of the sea. Both are inhospitable places where food and water are scarce. Both are often home to valuable trade routes, and connect important mercantile cities. Both feature vast expanses of empty wasteland, dotted with hidden treasures, and both are the homes of unusual and exotic giant races.
This book presents game statistics for the mythic desert giant and mythic ocean giant, both of which have unique abilities never seen elsewhere. Mythic desert giants (CR 14) can glide across the dunes as easily as if they were ice, can conjure sandstorms from thin air, and can bring their scimitars to life, flying through the air to fight on their own. Their counterparts, the mythic ocean giants (CR 17), can command the creatures of the seas, create great vortices, and even transform themselves into pure ocean water.