"It is Princess Harriet Hamsterbone to the rescue when Heady the hydra's egg is stolen, but her search leads her to a castle accessible only by a rat with a very long tail"--

While continuing to help his classmates solve their problems, Humphrey, pet hamster of Longfellow School's Room 26, faces many surprises, like rolling in a hamster ball, a substitute janitor who might be an alien, and the possibility of Mrs. Brisbane retiring.

"The laughs continue when Fido, the guinea pig that thinks she's a dog, has a pup that thinks she's a squirrel. A sequel to Guinea Dog"--

Humphrey the hamster is puzzled when unfamiliar students fill Mrs. Brisbane's classroom at summer's end, but he soon learns that his friends from last year are fine and that the new class needs his special help.

When Freddy's mother finally allows him to bring Harold, the class hamster, home for the weekend, Freddy has his hands full making sure that Harold does not escape.

Katie Carew, nicknamed Katie Kazoo by the class bully, wishes that she could be anyone but herself, but when her wish comes true and she turns into a hamster, she has to figure out what to do.

When the Willows move into a new house, Celia, the youngest of four children, traps an enchanted hamster, who reluctantly agrees to grant the children one wish in exchange for his freedom.

Learn about the traits of hamsters and how to feed and care for them.

Sam Waters is desperate to have a pet. But his parents say that first, Sam must prove he's responsible. So he takes an after-school job in a pet store called Little Shop of Hamsters. To his horror, Sam soon finds that cute, little hamsters can become very uncute monsters. Suddenly, Sam isn't fighting for a pet--he's fighting to survive!

After learning about Sherlock Holmes, Humphrey the classroom hamster follows clues to try and discover why Mrs. Brisbane is gone and Mr. E, a fun but not very educational substitute, is taking her place in Room 26 at Longfellow School.