The monstrous Turbo Toilet 2000 is determined to take revenge on George, Harold, and Captain Underpants.

With her perfect attendance record, Pinkalicious gets to be principal for the day, but when she wakes up sick, she worries that her big day will be ruined.--

When Professor Pippy P. Poopypants comes to Jerome Horwitz Elementary School to teach science, and he goes off the deep end because students make fun of his name, only Captain Underpants can save the school from the professor's perilous plot.

After the principal of P.S. 88 is turned into a frog by a bumbling magician, the frog bargains for the chance to act as principal until Mr. Bundy returns from his "family emergency."

After the principal of P.S. 88 gets caught up in a messy spell by one of his students, the other kids rally to help him out.

A little boy is sent to the principal's office.

After the principal and assistant principal of P.S. 88 are eaten by the Big Bad Wolf, the students must outsmart the wolf in order to get them back.

When Sarah Burton returns to her hometown as headmistress, she is full of ambition, determined to create a great school and to inspire her girls to take all they can from life. But in the aftermath of the First World War, the country is in depression and ideals are hard won. Lydia Holly, the scholarship girl from the shacks, is the most brilliant student Sarah has ever taught, but when her mother's health fails, her education must be sacrificed -...

When Mr. Lincoln, "the coolest principal in the whole world," discovers that Eugene, the school bully, knows a lot about birds, he uses this interest to help Eugene overcome his intolerance.

"Friends and pranking partners Miles and Niles face a tough challenge when their favorite goat and nemesis, Principal Barkin, is replaced by his stern, no-nonsense father, Former Principal Barkin, who turns the school into boot camp"--