1. Percy Jackson: Son of Poseidon, the sea god
2. Annabeth Chase: Daughter of Athena, the goddess of wisdom and warfare
3. Grover Underwood: Son of Hermes, the messenger god (though he is a satyr, not a demigod)
4. Thalia Grace: Daughter of Zeus, the king of the gods
5. Luke Castellan: Son of Hermes, the messenger god (though he turns out to be a traitor)
6. Nico di Angelo: Son of Hades, the god of the underworld
7. Bianca di Angelo: Daughter of Hades, the god of the underworld (deceased by the time of The Last Olympian)
It's important to note that Bianca is not technically part of the prophecy as she is already dead. However, she is crucial to the story as her death fuels Nico's determination to become stronger and play a role in the prophecy's fulfillment.