Gravity Falls
In February 2018, Hirsch used his Twitter account to announce an official "Gravity Falls" graphic novel, through a series of puzzle pieces that he would release throughout the day. Put together the puzzle pieces revealed the cover of "Gravity Falls: Lost Legends; 4 All-New Adventures!" which was written by Hirsch was released on July 24, 2018 and also became a "New York Times" Best Seller.