Captain Underpants #9: Captain Underpants and the Terrifying Return of Tippy Tinkletrousers

When we last saw George and Harold, they were headed to jail for the rest of their lives. What could be worse? How about being pulled from prison by a time-travelling tyrant named Tippy Tinkletrousers?!!? Now the boys are taking a trip back in time to the carefree days of kindergarten, when the scariest thing they had to face was not evil mad scientists or alien cafeteria ladies, but a sixth-grade bully named Kipper Krupp, the nephew of their clueless school principal.