Letterman Finds Nice Fit With "Captain Underpants"

Rob Letterman will direct an animated film based on author Dav Pilkey's popular kids book series "Captain Underpants" says Heat Vision.

The story centers on two fourth graders who are best friends and who draw comics that they sell on the playground. Their creation, Captain Underpants, becomes real when the duo accidentally hypnotize the school's mean principal who turns into an actual superhero.

Nicholas Stoller wrote the adapted script, after previously worked with Letterman on "Gulliver's Travels".

The book series began in 1997 and there now more than 50 million Pilkey books in print in the U.S. alone.