Beginning in 1996, Hey Arnold! took over for Doug as the Nickelodeon cartoon that revolved around a grade-school protagonist and his adventures with his public school friends, perceived bullies, and family. With Nickelodeon’s new programming block The Splat bringing back some of the channel's classic '90s series, here are some facts about Hey Arnold!

1. ARNOLD WAS CREATED WHILE CRAIG BARTLETT WAS WORKING ON PEE-WEE’S PLAYHOUSE.

He made the boy out of clay, since he was responsible for some of the iconic show’s “Penny” claymation cartoons.

2. ARNOLD APPEARED ON SESAME STREET.

Bartlett created three claymation shorts of Arnold, one of which, “Arnold Rides His Chair,” appeared on Sesame Street. While Bartlett worked as a writer on Rugrats in 1993, he showed all of his Arnold shorts to a Nickelodeon executive. The Hey Arnold! pilot was made one year later.

3. THE SIMPSONS CREATOR MATT GROENING GAVE BARTLETT SOME IMPORTANT ADVICE.

The designs for the Hey Arnold! characters can be traced back to Groening. He told Bartlett to design characters so they can be recognized from a distance, or in silhouette. Groening also happens to be Bartlett’s brother-in-law. Bartlett gave Groening a “special thanks” in a third season episode.

4. LISA GROENING CAME UP WITH HELGA’S INFATUATION WITH ARNOLD.

Matt Groening’s sister Lisa (yes, like Lisa Simpson), who is Bartlett’s wife, thought Arnold’s bully should also harbor a secret love for the one she tormented. Lisa didn’t want to see another “bully girl” similar to Angelica on Rugrats.

5. THE ORIGINAL PILOT NEVER RAN ON TV.

But it did run as a theatrical short before showings of Harriet the Spy in movie theaters. The pilot was remade as the first season episode “24 Hours to Live.” There are some notable differences between the original and the remake, like Arnold’s sweater.

6. OSKAR’S ACCENT IS MODELED AFTER BARTLETT’S FORMER BOSS AT RUGRATS.

Even though Oskar Kokoshka is from Czechoslovakia, he purposely sounds like the Hungarian Gabor Csupo. Klasky/Csupo was the animation company that produced Rugrats, Aaahh!!! Real Monsters, Duckman, and The Wild Thornberrys. Steve Viksten, the Hey Arnold! writer who voiced Oskar, sadly passed away last year at the age of 53 years.

7. HILLWOOD ISN’T A STAND-IN FOR ONE SPECIFIC CITY.

Bartlett claimed it’s a combination of his hometown Seattle; Portland, Oregon, where he went to art school; and Brooklyn.

8. BARTLETT LOOKS LIKE DJ NOCTURNAL/NASHVILLE NED.

The MJZZ and KDUDE radio personality Ned was drawn to resemble the Hey Arnold! creator, although Bartlett relates most to the main character.

9. SIX DIFFERENT ACTORS VOICED ARNOLD.

J.D. Daniels was the voice actor in the pilot/movie short. Toran Caudell (he was also Wolfgang), Phillip Van Dyke, Spencer Klein, and Alex D. Linz all portrayed Arnold at various points during the series’s run. Rusty Flood played Baby Arnold in “Parents Day” and Little Arnold in “Helga on the Couch.”

10. KIDS WERE USED AS THE VOICES OF THE CHILDREN.

Bartlett felt that using young voice actors imbued the show with the emotions and sadness of childhood. All of the Arnolds were pre-teens or teenagers. Francesca Smith was 11 when she began playing Helga Pataki. Jamil Walker Smith was 14 when he started out as Gerald. Justin Shenkarow was about to turn 16 when he began as Harold.

11. HELGA’S NAME WAS A TRIBUTE TO A NICKELODEON EXECUTIVE.

Helga’s middle name is Geraldine. It was a nod to Gerry Laybourne, an executive for Nickelodeon when Hey Arnold! began. She later helped create the Oxygen Network.

12. THE MOVIE WAS ONLY MEANT TO BE A TV MOVIE.

Hey Arnold! The Movie tested so well at a screening that network executives decided to release it in theaters. It made a disappointing $13.7 million at the box office.

13. THE SHOW'S COMPOSER PAID FOR THE MOVIE’S ORCHESTRA WITH HIS OWN SALARY.

Jim Lang switched out the originally intended synthesizer orchestra with an actual one for his 20 minutes of music. He used his entire paycheck for the movie to do so.

14. ARNOLD’S LAST NAME WAS NEVER OFFICIALLY REVEALED.

In a 2007 Q&A, a fan asked Bartlett which character said Arnold’s surname the most. Bartlett responded with, “Grandpa, of course.” This has led some viewers to speculate that his real name is Shortman.

15. A FINALE MOVIE AND A SPINOFF NEVER CAME TO PASS.

“The Jungle Movie” was meant to continue the story presented in the episode “The Journal,” where Arnold would look for his parents in San Lorenzo. Nickelodeon cancelled Hey Arnold! before the theatrical movie could be greenlit. The Patakis would have starred a 15-year-old Helga and run on Nick at Nite. It was darker in tone than the original show and the network eventually passed on Bartlett and Michelle Lamoreaux’s script.

16. BUT THERE MIGHT BE A REBOOT.

Nickelodeon president Russell Hicks announced last month that they are considering bringing Hey Arnold! back. In April, Bartlett himself announced that he was working with the network to bring Hey Arnold! back from the dead.