That pilot, Tome of the Unknown, became the catalyst for Over the Garden Wall. After working on other Cartoon Network shows including The Marvelous Misadventures of Flapjack and Adventure Time, the network expressed interest in McHale pitching a pilot. McHale first envisioned the show in 2004 and pitched it to the network in 2006. The show was the first miniseries on the network. Over the Garden Wall was broadcast throughout the week of November 3 to November 7, 2014. The series' voice cast also includes Christopher Lloyd, Tim Curry, Bebe Neuwirth, Chris Isaak, Shirley Jones, Thomas Lennon, Jack Jones, Jerron Paxton, John Cleese and Samuel Ramey.

Elijah Wood and Collin Dean voice the protagonists Wirt and Greg, and Melanie Lynskey voices Beatrice, a bluebird. The show is based on McHale's animated short film Tome of the Unknown, which was produced as part of Cartoon Network Studios' shorts development program. The series centers on two half-brothers who travel across a mysterious forest to find their way home, encountering a variety of strange and fantastical things on their journey. Over the Garden Wall is an American animated television miniseries created by Patrick McHale for Cartoon Network.

Over the garden wall chords