Captain Underpants and the Perilous Plot of Professor Poopypants Bk. 4

Professor Pippy P. Poopypants is a brilliant scientist, but his ridiculous name means no one takes his fantastic inventions seriously. And now he's on the rampage...He's armed with the fiendish Shrinky-Pig 2000 and he's prepared to use it! This is definitely a job for the world's only superhero with Wedgie Power.