Tethys

In the mythology of Ancient Greece, Tethys was one of the Titanesses, enormous god-beings which had been in existence since nearly the beginning of time.

Description
The Titaness of fresh water, including lakes, rivers and springs, Tethys was of the first generation, and married her brother Oceanus. The two had many offspring together, including the Oceanids (nymphs associated with the sea and rivers), Potamoi (fresh water gods), and the second-generation Titaness Metis.

Like her husband, Tethys appears to have taken no side during the war for the heavens known as the Titanomachy. She did, however, protect the goddess Hera during this period, who was apparently very grateful.

One account claims that it was Tethys and Oceanus, rather than Uranus and Gaia, who were the parents of the Titans, although this source conflicts with all others.