The Big Picture

• Paul McCartney's guest appearance on The Simpsons ensured Lisa remained a vegetarian to spread the message of animal rights.
• Other guest stars on the show, like Michael Jackson, had unique conditions for their appearances.
• The show has had several predictions come true, such as McCartney's influence on Lisa's vegetarianism.

When a TV series has been on the air for some time, there are bound to be continuity errors. The Big Bang Theory had Leonard (Johnny Galecki) explain to Howard (Simon Helberg) how the elevator's been out of order for two years, only for a later episode to show that Howard was there to witness the original explosion that actually knocked it out of commission five years earlier. So, how does a show like The Simpsons—soon to wrap up its 35th Season—deal with continuity? By not dealing with it at all. No matter how many times Homer (Dan Castellaneta) has brought Springfield to the edge of nuclear annihilation, he's right back in Sector 7G the following week. Maggie has the same pacifier she's had since the beginning, both Bart (Nancy Cartwright) and Lisa (Yeardley Smith) are perpetually at Springfield Elementary, never to move on to Springfield Junior High (is there even another school in Springfield?

However, there is one change that has been carried over that's quite unique, and it's one of the very few that has to do with the titular family itself. It's been in place since 1995, and the driving force behind it is none other than the living legend and former Beatle, Paul McCartney.

"Lisa the Vegetarian" Changes the Status Quo on 'The Simpsons'

"Lisa the Vegetarian," the fifth episode of The Simpsons seventh season, begins with the family visiting a fairy tale-themed amusement park, Storytown Village, and Lisa is captivated by the adorable little lambs at the petting zoo. They come home and settle in for dinner with an ill-timed feast of lamb chops. Lisa can't bring herself to eat any, as she keeps hearing the sorrowful bleating of the petting zoo lamb. Marge (Julie Kavner) offers Lisa rump roast, chicken breast, and even hot dogs, but to no avail—Lisa can't stop thinking about how they were once living creatures, and decides then and there to become a vegetarian.

Later on, Homer decides to host a barbecue, and Lisa brings a gazpacho as an alternative. After being ridiculed by the meat-loving attendees, Lisa takes a riding mower and drives off with Homer's roast pig, which she pushes off a slope before Homer and Bart can stop her. Back home, Homer and Lisa get into a heated argument which ends with Lisa leaving the house, angry and hurt by her family not respecting her new lifestyle choice.

Apu (Hank Azaria) later confides in Lisa and tells her that he serves tofu dogs at the Kwik-E-Mart, and that he has been for a while. He escorts Lisa to his rooftop garden, where she meets Paul and Linda McCartney, who are also vegetarians. They teach Lisa that it's okay to have her own views, but that she has to tolerate the views of others in return. Lesson learned, Lisa returns home, apologizes, but declares that she is going to remain a vegetarian.

Paul McCartney Is the Reason for Lisa's Vegetarianism

From that point on, Lisa was a vegetarian, with only one controversial exception where she ate a Scotch egg (she spit it out and was filled with "deep regret," so it doesn't count). While it certainly fits the character, why that particular trait came to be continuity is odd, that is until you hear the story behind it. When "Lisa the Vegetarian" was being written, McCartney was the only living member of The Beatles who hadn't appeared on the show. Ringo Starr guest-starred in 1991's "Brush with Greatness," writing back to Marge to thank her for her portrait of him, decades after receiving it. George Harrison was in the classic 1993 episode, "Homer's Barbershop Quartet," which was full of Beatles references from start to finish. McCartney was high on their wish-list of guest stars, and showrunner, David Mirkin, thought that the episode would appeal to McCartney, as he was a vegetarian himself. McCartney agreed to appear, but on the condition that Lisa remains a vegetarian for the rest of the series.

The staff agreed, and McCartney was on board. They also invited Linda McCartney to appear, as well, and she jumped at the opportunity, seeing the episode as a chance for her and Paul "to spread the vegetarian word to a wider audience." Not only did Paul and Linda appear, but Paul used the episode to poke fun at long-standing rumors of his "death" and the practice of backmasking hidden messages. In the show, Paul tells Lisa, "Linda and I both feel strongly about animal rights. In fact, if you play 'Maybe I'm Amazed' backwards, you'll hear a recipe for a really ripping lentil soup." But with the help of producers, he played one of the best guest star gags in the show's history, recording the recipe for his lentil soup, which was then reversed and played during the closing credits, with McCartney adding, "Oh, and by the way, I'm alive."

McCartney gave his reasoning for the request, saying, "We were a bit worried that she would be vegetarian for a week, then Homer would persuade her to eat a hot dog." And although the writers were tempted, Lisa still remains a vegetarian, true to their word. Hank Azaria gave a reason why he believes that they haven't, saying that, "The writers probably have not because they made that 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." As recently as 2020, Mirkin confirmed that McCartney still checks, "and he's always surrounded by nine or 10 lawyers, so it's quite frightening."

Paul McCartney Isn't the Only 'The Simpsons' Guest Star Who Had Specific Conditions for His Appearance

Paul McCartney's condition for his guest appearance on The Simpsons may have altered the course of the show going forward, but he isn't the only guest star to have placed conditions on their appearances on the show. Dustin Hoffman, who played a substitute teacher, Mr. Bergstrom, in Season 2, asked that his real name not be used in the credits, and suggested "Sam Etic" as a pseudonym. Bette Midler asked that her anti-litter campaign be promoted for her appearance, which the writers obliged by turning her into an anti-litter vigilante in "Krusty Gets Kancelled." Stephen Hawking had only one request for his first appearance, and per showrunner, Al Jean, "He did say at one point he did not want to be drunk onscreen. That was the only note we got from him. He didn't mind having a beer with Homer at Moe's [in the end of "Lisa's Brain"], but not more."

The strangest, though, just might be Michael Jackson's appearance in the first episode of Season 3, "Stark Raving Dad," an episode that is famously missing from Disney+. Due to legal restrictions, Jackson couldn't appear under his real name, and was credited as "John Jay Smith." His record label wouldn't allow for him to sing on the show, a problem given the "Happy Birthday Lisa" duet with Bart that closes out the show, forcing the show to bring out a Jackson impersonator by the name of Kipp Lennon to sing the song instead. This means that "Happy Birthday Lisa" was sung by Lennon pretending to be Jackson, while Jackson played a character named Leon Kompowsky who thought he was Jackson, with Jackson playing the role under the pseudonym John Jay Smith. Yeah, it was a lot.

The Simpsons is available to watch on Disney+ in the U.S.

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