A noteworthy book for young people: The Pig Scrolls, by Paul Shipton (2005). Looks like fun! Here's a summary from a Library Science website (?) [pdf]:
This hilarious story is set in Ancient Rome. Gryllus, who was once a crewman of Odysseus, tells how he was transformed into a pig and then chosen to save the world. Circe had turned Odysseus’s crew into pigs, but when she changed the crewmen back into their original forms, Gryllus, who was enjoying his life of leisure, elected to stay a pig. Unfortunately, his quiet life in the woods was interrupted one day by Sibyl, who informed Gryllus that he had been chosen by Apollo to save the cosmos. Gryllus thought Sibyl was crazy and ignored her, so Sibyl kidnapped him. On their journey to Delphi, they encountered monsters, gods, a strange goat herder and a man wearing trousers. Gryllus came to realize that the fate of the world really was in the hooves of a talking pig.
I'm not sure where I picked up this reference, but I've been meaning to post this for a while now...