Peter BlofisProtagonist of the story, son of Sally Jackson and Paul Blofis. Shy and polite in nature, but determined and loyal. Before Percy disappeared, he used to tell stories to the little kid, giving him basic knowledge of the Olympians, Camp Half-Blood, etc. Armed with the basics of what about the demigod world, not really good at handling weapons and defending himself.
Leon HamiltonA son of Demeter, and Peter's best demigod friend. When he was little, he was saved by a demigod and was brought to Camp Half-Blood, and Leon lived the duration of his life there.
Claire WilliamsA daughter of Apollo. Daughter to a former nun (which explains her catholic roots). Has a stoic attitude, although she has a soft side for her celebrity crush Nico di Angelo.
Leo Valdez aka Mr. Flamingo