The Old Man of the Sea who was the son of Pontus and Gaea and husband of Doris. They had 50 daughters: the Nereids. Nereus was a kind man and could foresee the future. He could also take many forms.

When Heracles was after the golden apples of the Hesperides, he caught Nereus in his sleep and held him until he had stopped transforming himself. After this, Nereus gave Heracles the directions to the gardens.