Will Arnett has replaced David Harbour in Behemoth! after Stranger Things star's sudden departure

Will Arnett has replaced David Harbour in Behemoth!.

The Is This Thing On? actor will be joining lead actor Pedro Pascal and the likes of Olivia Wilde, Eva Victor, Matthew Lillard, Margarita Levieva and Alexa Swinton in the drama following the news the Stranger Things star has departed Tony Gilroy's movie for personal reasons.

Production began in late October but insiders told Deadline the scenes involving David that need to be reshot are minimal as he was doing a lot of press for the final season of Stranger Things at the time, and adding Will to the cast shouldn't make the shoot go on any longer than planned.

Exact details of the Behemoth! story have been kept under wraps by Searchlight Pictures, though it is believed that the film - which Tony also wrote and is co-producing - centres around a cellist.

Will has recently be celebrated for his work in Is This Thing On?, in which he plays Alex Novak, who becomes a stand-up comedian by chance while on the verge of divorcing wife Tess (Laura Dern).