Captain Underpants Full Colour Series Book 9-12 by Dav Pilkey 4 Books- Ages 7-11
But why, you might ask, didn't the amazing Captain Underpants save the boys from this frightening fate?. Captain Underpants and the Revolting Revenge of the Radioactive Robo-Boxers (Book 10). Captain Underpants and the Tyrannical Retaliation of the Turbo Toilet 2000 (Book 11).