During one of his Twelve Labours to find his way to the Garden of the Hesperides in order to take the Golden Apples, Herakles wrestled with Nereus, the Old Man of the Sea, who was half-man half-fish. By the middle of the 6th Century B.C. the monster changes identity and becomes known as Triton. Cf. J. D. Beazley, Attic Black-Figure Vase-Painters, New York, 1978, p. 619, nos. 62-66 for similar.