Oceanid

In the mythology of classical Greece the Oceanids, sometimes Oceanides, were a group of numberless water-nymphs who presided over the many springs and rivulets of the land.

Description
Birthed from the Titan water deities Oceanus and Tethys the Oceanids, along with their countless brothers the Potamoi, were tasked with the rulership of all of the freshwater bodies of the known world. They were held in deepest respect by sailors of the time, who would pray and make sacrifices to them, believing that through their association with the other gods of the waters, they could grant them favour conditions for their travels. In addition to these functions, the Oceanids were tasked by mighty Zeus himself with watching over the children of the world, although how they went about this is unknown.

Many of Oceanids were also known to have married other Olympian gods, becoming some of the more commonly worshiped deities and important water-goddesses in their own right. Several of these Oceanids bore children, including other water-nymphs and even further generations of gods.

When the Titan Prometheus was sentenced to his punishment by Zeus for stealing fire and giving it to mortals, the Oceanids came to him from beneath the Earth in order to console the giant. They also gave comfort to Persephone after she was kidnapped by Hades; this may have been due to the head of the Oceanids, Styx, being the personification of the great river of the Underworld which bore her name.