David Harbour has exited the upcoming drama Behemoth! after being overwhelmed by the Stranger Things series finale. The film, directed by Tony Gilroy, will now star Will Arnett in Harbour's role alongside Pedro Pascal and Olivia Wilde. Production continues with minimal reshoots needed.
David Harbour, known for his role as Jim Hopper in Netflix's Stranger Things, has stepped away from Tony Gilroy's upcoming drama Behemoth!. Searchlight Pictures confirmed the departure to Variety on January 7, 2026, following the airing of Stranger Things' series finale on December 31, 2025. Insiders told Variety that Harbour was overwhelmed by the intense promotional demands and emotional weight of ending the five-season, 10-year run.
The film, which began production in late October 2025, follows a musician from a family of musicians returning to Los Angeles, described as a love letter to the music of movies and its creators. Gilroy, acclaimed for the Bourne films and the Star Wars series Andor, wrote the script and is directing, producing alongside Sanne Wohlenberg and his brother John Gilroy. The cast includes Pedro Pascal, Olivia Wilde, Matthew Lillard, Eva Victor, Margarita Levieva, and Alexa Swinton.
Harbour's role has been recast with Will Arnett, known for Is This Thing On and Arrested Development, according to Deadline. Sources indicate that scenes requiring reshoots are minimal, as Harbour's involvement was limited due to his Stranger Things commitments, and this will not delay the schedule.
Harbour's exit comes amid personal challenges. He skipped the Stranger Things Final Season Celebration at the Paley Center on December 18, 2025, citing a scheduling conflict. A TMZ report from the day prior detailed an incident at an Encinitas, California, bar where Harbour was accused of taking a fan's hat, though it was returned without violence. Additionally, November 2025 reports alleged bullying of co-star Millie Bobby Brown, which she denied, and they appeared united at the Season 5 premiere. Harbour's divorce from Lily Allen, who referenced alleged infidelity in her October 2025 album West End Girl, has also drawn attention. Harbour, diagnosed with bipolar disorder at age 26, has spoken openly about his struggles with alcoholism.
Despite the exit, Harbour remains attached to Avengers: Doomsday as Red Guardian and Violent Night 2. Stranger Things Season 5 achieved 31.5 million views on New Year's Day 2026, ranking ninth on Netflix's Most Popular English TV list with 105.7 million total views.
