Captain Underpants and the tyrannical retaliation of the Turbo Toilet 2000

Captain Underpants and the Tyrannical Retaliation of the Turbo Toilet 2000 is a novel by Dav Pilkey and the eleventh (and penultimate) book in the Captain Underpants series. It was published on August 26, 2014, and features the second and final speaking appearance of the Turbo Toilet 2000, as well as the first appearances of George and Harold's duplicates born through time travel, Yesterday George and Yesterday Harold; as well as the four's new pets and Crackers and Sulu's offspring, Dawn, Orlando, and Tony, who are hybrids between a bionic hamster and a pterodactyl.