Cartoonist, author, and illustrator Rob Harrell was approached by producers at a Comic-Con event about his popular, children's graphic novel, Monster on the Hill. This chance meeting led to his book being optioned for film, but it took eight years for the project to get greenlit and produced. Harrell was invited to meetings with the producers to provide his input during the development process, but his involvement was otherwise very limited. The project resulted in the animated movie, Rumble, which was produced by Paramount Animation, WWE Studios, Walden Media and Reel FX Animation Studios. It was released in the United States on December 15, 2021 on Paramount+, and is currently available on several other streaming channels. Harrell was disappointed it was released during the pandemic and went straight to streaming, but enjoyed the experience overall. He does caution authors that when you sign an option agreement for your book, you are assigning rights to your book's content over to someone else, and there is no guarantee that the adaptation will be at all similar to your book. Had he known then what he knows now about book to screen adaptations, he would have asked for more involvement in the contract so that the adaptation more closely followed his book.