This depiction of King Neptune is presented at the entrance to Neptune's Kingdom - an arcade on the Santa Cruz Baordwalk.
As for Neptune, Wikipedia (
visit link) informs us:
"Neptune ... was the god of freshwater and the sea in Roman religion. He is the counterpart of the Greek god Poseidon. In the Greek-influenced tradition, Neptune was the brother of Jupiter and Pluto; the brothers presided over the realms of Heaven, the earthly world, and the Underworld. Salacia was his consort.
Depictions of Neptune in Roman mosaics, especially those of North Africa, are influenced by Hellenistic conventions. Neptune was likely associated with fresh water springs before the sea. Like Poseidon, Neptune was worshipped by the Romans also as a god of horses, under the name Neptunus Equester, a patron of horse-racing."