List of Percy Jackson and the Olympians characters
Nemesis: The goddess of revenge and balance. She never makes any actual appearances in the books, but she is the mother of Ethan Nakamura, who appears in The Battle of the Labyrinth and The Last Olympian. Ethan mentions her in both The Battle of the Labyrinth and The Last Olympian. She is mentioned by Grover as a "god" when he talks to Percy at the start of the series.