The sixth book in this exciting new chapter-book series from the bestselling creator of Captain Underpants!
Ricky Ricotta doesn't want to spend the day with Cousin Lucy; she always wants him to play princess. But this game of princess gets dangerous when Sergeant Stinkbug kidnaps Lucy and tries to take over the planet. Together, Ricky Ricotta and his Mighty Robot must defeat the Stinkbugs and save Earth!