I
Percy's Latin teacher/mentor
Mr. Brunner
Percy's friend/daughter of Athena
Annabeth
centaur who trains heroes
Chiron
true identity of Aunty Em
Medusa
creature that is part lion, part goat, with a snake as a tail
Chimera
three-headed dog that guards the entrance to the Underworld
Cerberus
what makes Annabeth become invisible
the deadline to return Zeus's lightning bolt
summer solstice (June 21)
Percy's mom
Sally Jackson
Percy's nemesis/daughter of Ares
Clarisse
the director of Camp Half-Blood
Dionysus
god of war, Aphrodite's lover
Ares
father of the "big three"
Kronos
food of the gods
ambrosia
name of Percy's sword
Riptide
600th floor of Empire State Building
Percy's algebra teacher/monster
Mrs. Dodds
Percy's supposed friend/son of Hermes
Luke
part human, part goat
satyr
god of the wild, shepherds who disappeared two thousand years ago
Pan
what the nymph of the ocean gives to Percy
3 pearls
Zeus's symbol of power
lightning bolt
pink poodle who helps Percy, Grover, and Annabeth
Gladiola
location of entrance to the Underworld
DOA Recording Studio in Los Angeles
Percy's stepfather
Gabe
the "big three"
Zeus, Poseidon, Hades
part human, part bull
minotaur
daughter of Zeus whose memorial is a giant pine tree at the camp
Thalia
the waterbed salesman who stretches human beings
Crusty (Procrustes)
Poseidon's symbol of power
trident
where Percy, Grover, and Annabeth enter a time warp
Lotus Hotel and Casino
How Sally takes care of Gabe
she uses Medusa's head to turn him into a statue
Percy's best friend
Grover
three monsters who assist Hades in the Underworld
the Furies
resides in the attic of the main house at the camp
the Oracles
goddess of the rainbow who delivers messages
Iris
ferryman who guides souls across the river into the Underworld
Charon
Hades's symbol of power
Helm of Darkness
the golden blood of gods
ichor
the thief who stole both the lightning bolt and the Helm of Darkness
Luke