"Tome of the Unknown: Harvest Melody", usually shortened to "Tome of the Unknown", is a 2013 animated short film created by Patrick McHale and produced by Cartoon Network Studios. The film serves as the inspiration and pilot for the miniseries Over the Garden Wall, which premiered in 2014. In the film—which is narrated by Warren Burton—Wirt (Elijah Wood), his brother Gregory (Collin Dean), and Beatrice (Natasha Leggero), a bluebird, head to the big city in search of an arcane book of all known things, meeting a vegetable man along the way.

McHale initially pitched the idea to Cartoon Network as a three-season television series, but was asked to develop it into a feature film for Cartoon Network's planned feature film department. He had trouble rewriting the series into a feature, and it was ultimately put on hold when McHale went to work on Adventure Time. Several years later, Cartoon Network asked McHale for another pitch. He reworked his pitch for Tome of the Unknown, which was accepted as a pilot and made into a short film. Released in 2013 to multiple film festivals, Tome of the Unknown has received several accolades.