Long ago "The Simpsons" ceased being The Little Engine That Could. At this point, it is The Gigantic Engine That Can Never Be Shut Off. Today, nearly halfway through its 26th season, it's aired 561 original episodes and earned billions of dollars for a lot of people — despite featuring characters with four fingers on each hand.



But even the most loyal "Simpsons" viewers can't know everything about the beloved series, which premiered 25 years ago, on Dec. 17, 1989 — so here's a collection of those lesser-known tidbits.

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1. Paul and Linda McCartney agreed to lend their voices to the 1995 episode “Lisa the Vegetarian”on the condition that the character of Lisa remain a vegetarian throughout the run of the series. She still is.



2. Substitute teacher Mr. Bergstrom, from the 1991 episode “Lisa’s Substitute,” was voiced by Dustin Hoffman, but the actor preferred to use the cheeky alias Sam Etic (a.k.a. “semitic”) instead.

3. Groening himself provides the pacifier-sucking sound for baby Maggie.

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4. The names Marge, Homer, Lisa, Maggie and Patty are all taken from creator Matt Groening’s real-life parents, sisters, and aunt. But Bart is simply an anagram of “Brat.” As for the name “Simpson,” Groening found it appropriate to feature a surname that literally described “the son of a simp.”



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5. The “The City of New York vs. Homer Simpson” episode of the series (from 1997) didn't air in syndication for five years after the 9/11 attacks due to its focus on the World Trade Center.



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6. Why are the Simpsons characters yellow? Because Groening thought seeing flashes of yellow would stop channel surfers in their tracks.

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7. God and Jesus are the only "Simpsons" characters with five fingers. The others all have four.

8. Conan O’Brien was a writer-producer on "The Simpsons"from 1991-93.

9. Each of the six principal "Simpsons" voice stars — Dan Castellaneta, Julie Kavner, Nancy Cartwright, Hank Azaria, Yeardley Smith and Harry Shearer — earns $300,000 per episode, after taking pay cuts from $400,000 in 2011. When the show launched in 1989, they earned $4,000 each per episode.

10. Principal Seymour Skinner’s real name is Armin Tamzarian. And Comic Book Guy's name is Jeff Albertson.

11. The series features a coffee house called Java the Hut, a soup kitchen called Helter Shelter, a pastry shop called The French Confection and the gun store Bloodbath and Beyond. (And that's just a smattering of the punny store names.)

12. Dan Castellaneta’s “D’oh!” is an homage to Jimmy Finlayson’s “Doooh!” in the Laurel & Hardy films. It is written in scripts simply as “annoyed grunt.”

13. Danny Elfman required just two days to compose the now-iconic "Simpsons" theme song in 1989.

14. Groening called the town Springfield because there are literally dozens of Springfields across the country, so the series would be identified with no single state.

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15. Krusty the Klown was originally created to be Homer’s secret identity, as Homer knew Bart worshiped Krusty, if not him. But Groening ultimately thought the disguise gambit too complicated, so it was scrapped.



16. In 1998, Time magazine named Bart Simpson one of the most influential “people” of the century.

17. In 1997, there was a contest to win a fully-furnished exact replica of the “Simpsons” house in Clark County, Nev. The winner could choose to either stay in the home or trade it for $75,000. The winner took the money. The house was ultimately stripped of its "Simpsons” décor before being sold.

18. The voice actors who play Homer and Marge in the French dubbed version of the show, Phillipe Peythieu and Veronique Augereau, got married in real life in 2001 after having met on the show in 1989.

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19. Following Phil Hartman’s death in 1998, the show retired all of his characters, including actor/eternal spokesman Troy McClure and attorney Lionel Hutz.



20. The 1992 episode “Stark Raving Dad” features the voice of Michael Jackson talking, but not singing. It was Jackson’s idea to use sound-alike Kipp Lennon instead.

21. Prior to "The Simpsons," the longest running prime-time animated series on network television was "The Flintstones," which ran for six seasons between 1960-66.

22. Bart’s best friend, Milhouse Van Houten, has a unusual middle name: Mussolini.

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23. The sale of "Simpsons" toys and figurines is illegal in Iran.



24. Since launching in 1989, the series has featured more than 600 guest stars, easily the most of any scripted series in television history.

25. If "The Simpsons'"characters had aged in real time, Homer would be 62 years old, Marge 61, Bart 36, Lisa 34 and Maggie 26. And family pet Santa’s Little Helper would be 196 in dog years.

Ray Richmond is the author of the 1997 episodic compendium The Simpsons: A Complete Guide to Our Favorite Family (HarperCollins). It is now, sadly, less than one-third “complete.”

