The Simpsons writer reveals the one celebrity guest star they're still trying to book after nearly 4 decades

The Simpsons has played host to a long list of celebrity guest stars over the years, but showrunner Matt Selman has now revealed which A-lister continues to elude them.

The writer and producer gave an interview to People on the eve of the show's 800th episode, where he shared that his team has written "great stuff" for a certain comedy legend, but they've yet to accept an invitation to Springfield.

The mystery person? Will Ferrell, of Saturday Night Live, Anchorman and Elf fame.

Ferrell's career was only getting started during The Simpsons' early seasons; he later became a household name in the early 2000s, when the animated series had recently exited its so-called 'golden age'.

As of season 37 (currently airing), The Simpsons is widely considered to be lacking the creative prowess that made it a global phenomenon, but it still has no trouble attracting big stars to its quirky town.

The 800th episode to premiere on Fox boasts voice roles for Kevin Bacon (Sirens) and Quinta Brunson (Abbott Elementary) as well as The Pitt stars Noah Wyle, Taylor Dearden and Katherine LaNasa.

Selman explained that the premise of the episode addresses the "emotional rollercoaster of pet ownership," and expressed excitement over a speech given by Marge Simpson (Julie Kavner) at the end.

"I think it's as good as anything that the show has ever done in the spirit of [co-creator] James Brooks' harsh, tortured, real view of what it's like to be a modern, emotional person in modern times," he elaborated.

"It's a love letter to the show. It's a love letter to pets. It's a love letter to Marge. I'm so proud of it."

Other notable names to have popped up in The Simpsons credits over the past year include Stephanie Hsu (Everything Everywhere All at Once), Viola Davis (The Woman King), Idris Elba (Hijack), Carrie Coon (The White Lotus) and Kieran Culkin (Succession).

Could Selman's recent admission lead to Ferrell's name on a future guest list? The actor has a few years to decide, as The Simpsons is confirmed to be continuing until at least season 40, with a second feature film also in the works.

The Simpsons is available to stream on Disney Plus.

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