Glaucus is a man with the bottom half of a fish traditionally called a merman. He was once a mortal. Originally a fisherman and diver of Boeotia, he once ate a magical herb and leaped into the sea, where he was changed into a god and endowed with the gift of prophecy. forcing him to dwell forever in the sea. Glaucus was initially upset by this side-effect, but Oceanus and Tethys received him well and he was quickly accepted among the deities of the sea, learning from them the art of prophecy.