Demigod son of Poseidon, wields water powers and sword Riptide to protect Camp Half-Blood.
Percy initially struggles with the revelation but ultimately accepts Tyson as family.
Tyson is revealed to be a previously unknown son of Poseidon, making him Percy's half-brother.
Their competitive relationship creates tension before becoming temporary cooperation.
Clarisse calls Percy a one-quest wonder, and she is selected instead of him to lead the official quest.
Luke's plan directly threatens Percy, Camp Half-Blood, and Olympus.
Luke poisons the tree protecting camp, kidnaps Grover, and plans to use the Fleece to destroy Olympus.
They are central quest partners who rely on each other's abilities.
Percy and Annabeth leave camp together to retrieve the Golden Fleece and repeatedly fight alongside each other.
Their cooperation drives the rescue mission and the journey across the Sea of Monsters.
Percy joins Annabeth and Grover in leaving camp to rescue Grover and pursue the Golden Fleece.
Mr. D controls official quest authorization at camp.
Mr. D denies Percy and his friends permission to undertake the quest, then claims the idea and selects Clarisse.
Hermes provides crucial assistance during the rescue effort.
Hermes helps Percy, Annabeth, and Tyson track Grover to Luke's yacht.
Percy opposes the cyclops to save Grover and obtain the healing artifact.
Percy and the group confront Polyphemus in his lair, retrieve the Fleece, and trap him.
Thalia's resurrection expands the prophecy's possible subject beyond Percy.
At the end, Percy realizes that the prophecy may also refer to Thalia because she is the daughter of Zeus.
Explore the full interactive character relationship map of Percy Jackson: Sea of Monsters
Related entry on Wikidata (Q3899725), public domain (CC0).