Paul McCartney reportedly was the person who convinced writers on The Simpsons to make Lisa a vegetarian.

The legend has been a staunch animal rights advocate for years and Simpsons vet Hank Azaria revealed that Macca only agreed to appear on the show if they turned a character into a vegetarian.


"I think it was really cool that he stuck that in," Azaria told the Huffington Post.

"I can tell you, over the years, they were tempted a bunch of times to have Lisa break her vegetarian vows."

Despite the temptation Azaria adds that she will remain steadfast, adding:

"They made a vow to Sir Paul. No, you don't break a knight's vow. As we've learned from 'Game of Thrones,' you do that at your own risk."