Captain Underpants and the Terrifying Return of Tippy Tinkletrousers Full Colour Edition (Book 9), Paperback/Dav Pilkey

In their ninth epic adventure, George and Harold encounter a familiar face - Professor Poopypants! He now goes by the name Tippy Tinkletrousers and is determined to seek revenge for all of the teasing his old name inspired. Now it's up to George, Harold, and the amazing Captain Underpants to stop Tippy Tinkletrousers before it's too late!