Nate Hopper has left his SVP of creative affairs position at Sony Pictures Entertainment to oversee a screen expansion of writer Mo Willem’s publishing franchises that’s currently underway at LA-based Stampede Ventures.

HBO Max signed a multi-year development deal with Willems in 2020, and also ordered animated specials Don’t Let the Pigeon Do Storytime (2020) and Naked Mole Rat Gets Dressed: The Underground Rock Experience (2022, pictured).

Building on this interest in the author’s books, Stampede is now working on an animated series called Unlimited Squirrels! for Cartoon Network and HBO Max, as well as a live-action pilot for a show concept based on his New York Times best-selling CAT the CAT book series.

Based in LA, Hopper reports to Stampede CEO Greg Silverman in his new role. His credits at SPE include animated features such as Open Season (2006), Cloudy With a Chance of Meatballs (2009) and Paws of Fury, which premiered theatrically in July.

Last year, Stampede teamed up with United Talent Agency to launch a HappyNest animation incubator for kid-friendly projects. The companies hired former MGA Entertainment exec Sadaf Cohen Muncy, who used to oversee content for brands like L.O.L. Surprise! and Bratz, to be serve as the the initiative’s head of development and production.