Believed by Eorzean fisherfolk to be the spawn of Thalaos─legendary creator of seas. It is, however, more likely to be no more than an overgrown little Thalaos.
Erratic flows of aether released after the Calamity not only resulted in a warping of the landscape, but of the creatures that dwell upon it as well. Such is the case of the Nepto Dragon─a little Thalaos grown to epic proportions.