Nereus

"Curse that upstart, I was here first."

- Nereus to Percy Jackson

Nereus is the god of the sea's rich bounty of fish, but he is better known as the "Old Man of the Sea" and is said to know everything, even tidbits of information concealed from the Oracle of Delphi. Like many of the other sea-gods, Nereus was a master shapeshifter, however, not much is known about his past, though he claims to have existed before Poseidon, which whom he calls an "upstart", stating that "I was here first!" If captured, he will allow his captor to ask him one question.

History
Nereus, a sea-deity, was a son of Gaea, by her son, Pontus. Apollodōrus gives him Terra for his mother. His education and authority were in the waters, and his residence, more particularly, was in the Aegean seas. He had the faculty of assuming what form he pleased. He was regarded as a prophet; and foretold to Paris the war, which the rape of Helen would bring upon his country.

When Hercules was ordered to fetch the golden apples of the Hesperides, he went to the Nymphs inhabiting the grottoes of Eridanus, to know where he might find them; the Nymphs sent him to Nereus, who, to elude the inquiry, perpetually varied his form, till Hercules having seized him, resolved to hold him till he resumed his original shape, on which he yielded the desired information.

Nereus had, by his sister Doris, fifty daughters called Nereids. They dwelt in the Aegean Sea in ancient times, but he moved to the San Francisco Bay with the gods who moved to New York. Hesiod highly celebrates him as a mild and peaceful old man, a lover of justice and moderation.

The Titan's Curse
Following advice from Apollo, Percy Jackson found Nereus on the docks of San Francisco, California, after dressing up in old clothes found by Zoe Nightshade. As Nereus is tired of being sought by demigods for answers to their questions and just wants to be left alone, Percy has to catch him long enough to ask one question. However, Percy tricked Nereus into jumping into the water with him holding on, making Percy stronger and overpowering him. During the fight, Nereus shape-shifted into different types of animals, including a a seal, a killer whale, and an eel to shake off Percy's grasp. However, his tossing and shape-shifting didn't work well leaving Nereus confused as to why Percy didn't drown at all, and Percy revealed that he was a son of Poseidon, much to Nereus' dismay. He eventually conceded the struggle and agreed to answer the heroes' question. Percy asked him for the location of the monster that Artemis, goddess of the moon and the hunt, had been tracking. Nereus said that the question was too easy and simply pointed to the Ophiotaurus, the creature that had been following Percy and his friends during the events of their quest. In Percy's confusion, Nereus changes into a goldfish and escapes into the sea.

The Son of Neptune
When Percy, Hazel Levesque, and Frank Zhang are sailing out of San Francisco Bay, Hazel becomes so sea sick that she thinks she is hallucinating when she sees him as an old homeless man hanging around a bunch of sea lions. When he sees Percy, he remembers their previous encounter, and points his finger at Percy as if to say, Don't even think about it.

Appearance
Nereus is described as looking like Santa Claus's evil twin, he is fat and has a white beard that has turned a shade of yellow. Nereus was wearing pajamas and a fuzzy bathrobe. He is also described as having a bad smell, like hot seaweed, dead fish and brine. Percy said that "If the ocean had an ugly side, this guy was it".

Abilities

 * Able to change shape into aquatic animals, in The Titan's Curse he changed into a seal, killer whale, eel, and goldfish while fighting Percy. However he also may have the power to shape-shift into anything, including inanimate objects.
 * Extensive (possibly unlimited) knowledge, including information unknown to the Oracle of Delphi.

Children

 * With the Oceanid Doris:
 * Delphin
 * Glaucus
 * Nerites
 * The Nereids, Amphitrite, Thetis, Psamathe, Galatea, Ploto, Thoe, Sao, among others.

Trivia

 * Nereus appears to have been the personification of the sea in its calm and placid moods.
 * After Poseidon, Nereus seems to be the most important of the sea-deities.