The fifth episode of the Johncast!
Credit to Kevin MacLeod for his awesome music from Incompetech, including Overworld, which I used in this episode.
"Overworld"
Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 3.0
http://creativecommons.org/licenses/by/3.0/
Thanks to audioblocks.com and orangefreesounds.com, for the awesome sound effects and music.
Here is the riddle's answer: A chalkboard!