Famously, Paul McCartney and his late wife Linda appeared in the Simpsons episode Lisa The Vegetarian back in 1995.
After bonding with a lamb at a petting zoo, Lisa later pledges to stop eating meat after meeting the famously veggie couple on the roof of the Kwik-E-Mart (turns out they're old friends with Apu).
Speaking to the Radio Times, David Mirkin, longtime Simpsons executive producer and showrunner – and a vegetarian himself – said that he does occasionally bump into McCartney in Hollywood.
And the Beatles legend will invariably enquire as to Lisa's continuing status as a non-meat eater.
“He always checks. And he’s always surrounded by nine or ten lawyers so it’s quite frightening,” Mirkin said.
He adds that he's always 'happy to comply' with McCartney's request.
The episode was the fifth of the seventh season of the show, and finds Lisa clashing with Principal Skinner (who brands her an agitator) and Homer, after she steals a suckling pig her father was planning to barbecue.
Eventually, she succumbs to social pressure, biting into a Kwik-E-Mart hotdog, only for Apu, a secret vegan, to inform her that it's made of tofu.
She's then given access to the secret garden atop Apu's convenience store, where she meets the McCartneys, pals of Apu from the Beatles' time in India.
Read more: Disney+ launch line up
He then reveals that if she plays his solo single Maybe I'm Amazed (which also closes the episode) backwards, it reveals 'a recipe for a really rippin' lentil soup'.
The episode is often regarded as an all-time classic, and followed guest appearances from Ringo Starr in the second season episode Brush with Greatness, and George Harrison in fifth season episode Homer's Barbershop Quartet.
To catch up with some of those classic eps, 30 seasons of The Simpsons catalogue are now available to stream in the UK on Disney+.