This is the fifth hilarious adventure in the Captain Underpants series. In this installment, fourth-graders George Beard and Harold Hutchins face their most formidable female villain yet: their power-mad teacher, Ms. Ribble. After the boys accidentally spill the principal's experimental formula on her, she transforms into the supervillain The Wicked Wedgie Woman, gaining the power to give paralyzing wedgies and transform into a terrifying, hairy monster. George and Harold must once again rely on the mighty, crime-fighting Captain Underpants to save the school. The book is filled with flip-o-rama pages, silly humor, and gross-out gags as the heroes try to defeat the wedgie-obsessed monster and return Ms. Ribble to normal.