Percy's girlfriend and a daughter of the goddess Athena; known for her intelligence and resourcefulness, she supports Percy in both personal and divine crises.

A satyr and Percy’s loyal best friend, who has accompanied him on numerous adventures; he resides and works at Camp Half-Blood.

Once human and now an immortal cupbearer to the gods; his desire to retain his immortality is challenged in the story.

The goddess of youth who places high value on maintaining her youthful appearance and struggles to understand mortal perspectives.

The goddess of the rainbow who helps demigods communicate through Iris-messages; she is a former cupbearer to the gods and values order in her world.

The god of old age, appearing as an elderly man, who presents as a challenge through his representation of mortality and aging.

A river god resembling a yoga instructor who interacts briefly with Percy when he enters the water to clean Iris's staff.

The god of the sea and Percy's father, who is largely absent but takes a small step toward acknowledging Percy's life and achievements.

The king of the gods, known for his arrogance and sense of superiority; he imposes unique challenges on Percy, demonstrating his disfavor toward him.

A Nereid working as a guidance counselor at Percy's high school, offering sporadic and incomplete support in navigating challenges at school.