Amphitrite

"This is my, er, wife, Amphitrite"

- Poseidon

Amphitrite (Αμφιτρίτη in Ancient Greek) is a sea-goddess, an Oceanid. Amphitrite is the daughter of Oceanus and Tethys and wife of Poseidon.

History
After her father was replaced as the ruler of the seas by Poseidon, Amphitrite became his wife and the Queen of the Ocean. They had a son, Triton, his father's heir.

Appearance
"To his right stood a beautiful woman in green armor with flowing black hair ans strange little horns like crab claws."

- Percy Jackson

Amphitrite is beautiful, with flowing black hair and little horns like crab claws. She wears green armor. Her little crab Horns maybe an inheritance from her Father, Oceanus.

Personality
"Excuse me, my lord. I am needed in the battle."

- Amphitrite

Amphitrite is a formal sea goddess, calling her husband 'my lord'. She is proud and haughty to Percy, but is probably otherwise when she is speaking to others. She seems hurt by her husbands' liasons, and probably wasn't happy when Poseidon promised on the River Styx that he wouldn't have anymore demigod children, but it was not kept, resulting in Percy, who it seems Amphitrite will never forgive. In myths though, she is not jealous of her husband's affairs with mortal women, but doesn't approve of it either.

The Last Olympian
Amphitrite is seen talking strategy with her husband Poseidon in the throne room of their ocean floor palace, along with their son Triton. Percy joins them, and Amphitrite treats him coldly, as he is the proof of her husband's unfaithfulness. Percy expects nothing else, and feels sorry for her that she doesn't have a faithful husband. She is worried how Oceanus is attacking and how Poseidon is losing power to the former God of the Sea.