Extra Crunchy CD o' Fun

The Captain Underpants Extra Crunchy CD o' Fun is a disc that was included in the Collector's Editions of the books. It contains 10 songs with lyrics by Josh Katz and Mike Pruesse, an executable flash game, an executable music video, a printable poster, a featurette about Dav Pilkey, printable coloring sheets, and an 800 x 600 computer background.

The disc was first released in 2005, though it was produced in 2004. Another version was released a year later titled The Super Silly CD o' Fun, which features songs by Koji Matsumoto.