The Master of the Waters is one of the large Sea Kings and inhabits the waters around Long Ring Long Land.
It is yellow, with red spots and fins on its head and sides. It is huge, as all Sea Kings are. It has a lot of sharp, pointed teeth, two small eyes, a big tongue, and flat nostrils.
He is a renowned problem for passing ships and local folk around Long Ring Long Island. Like other Sea Kings such as Lord of the Coast, he is very aggressive and fierce. Most people who encounter him seem to be very afraid of him.
He appeared when Tonjit with Shelly wanted to go to the next island to find their friends. Aokiji helped these two by freezing the water along with the monster, so they can walk easily on the ice for about a week. It is unknown if it is still alive or not.