Across
- 2. The Greek god of the sky and keeper of the Lightning Bolt
- 4. The last obstacle to the Underworld who lures customers to his water beds.
- 6. Daughter of Ares who bullied Percy
- 9. Daughter of Athena
- 10. The Greek god of the Underworld
- 11. Son of Hermes and the thief of Zeus' Lightning Bolt
- 12. The major gods and goddesses who rule at Mount Olympus
- 15. The Greek goddess of wisdom and Zeus' daughter
- 17. Echidna's part-lion, part-goat, and part-snake monster son
- 18. AKA Mr. D, director of Camp Half-Blood and the Greek god of wine
- 20. The monster who is Half-Man and Half-Bull
- 22. He ferries dead spirits into the Underworld across the River Styx
- 23. The Guardian of Percy and he is a Satyr
- 24. Percy's mother
Down
- 1. The deadly trio who guards Hades and the Underworld. One of them is known as Mrs. Dodds
- 3. The titan who speaks to Percy in the Underworld and causes Luke to steal Zeus' Lightning Bolt
- 5. Three-headed dog who guards the entrance to the Underworld.
- 7. Chimera's mother
- 8. Gorgon who disguised herself as Aunty Em
- 13. The Greek god of the sea and father to Percy
- 14. Son of Poseidon and he was framed for stealing Zeus' Lightning Bolt
- 16. The Greek god of war who gives Percy, Annabeth, and Grover a mini-quest to retrieve his shield
- 17. AKA Mr. Brunner, Percy's favorite teacher and he is Centaur
- 19. Percy's stepfather
- 21. Daughter of Zeus who sacrificed her life in order to protect Annabeth, Luke, and Grover