Percy- Harry (Obviously)
Annabeth- Hermione (I know Annabeth and Ginny both date main characters, and I love Annabeth, but she is too high maintenance (like Hermione, who I also like) to be like Ginny, and she and Hermione are both really smart.)
Tyson-Hagrid
Mrs. O'Leary - Fang
Chiron - Dumbledore
Dionysius- Slughorn
Poseidon - James
Hannibal - Buckbeak
Grover- Neville
Zeus - Fudge
Clarisse- Draco
Calypso - Cho
Piper - Lavender
Kronos - Voldemort
Luke - Snape
Travis and Connor - Peeves
Aphrodite - Ludo (helps main character along)
Hera - Bellatrix (REALLY annoying)
Jason - Cedric