Hey Arnold! was a Nicktoon that premiered in October 7th 1996, along with KaBlam! on Nickelodeon. A movie, fittingly titled "Hey Arnold! The Movie" was released in 2002.

Arnold, never telling us his last name, was raised by his grandparents in the Sunset Arms boarding house after his parents disappeared after going on one last rescue mission. The boarding house was filled with a few other people, Ernie, a short chunky man who demolished buildings, Mr. Hyunh, a quiet oriental man, Oskar and Suzie Kokoshka, a married couple who fought very often, and Mr. Smith, a man who keeps to himself and is mentioned only a few times because he is rumored to work for the CIA.

P.S 118, the school Arnold attends, for 4th grade every season, has many interesting students, such as Arnold's best friend Gerald Johanssen, Helga Pataki, the girl who "hates" Arnold but is really madly in love with him (remember the locket and the gum statue in her closet), Pheobe, the best friend and sidekick of Helga. Other friends and classmates of Arnold were Sid (long nose, beetle boot boy), Stinky (tall, nasaly voiced [YAHOOO SODA], Harold (bully one day, best friend the next), Eugene (I'm okay, CLUMSY), and Rhonda (Fashionable rich girl).

Hey Arnold looks as if it takes place in New York City, seeing as a bridge resembling the Brooklyn Bridge, and the New York skyline were shown. Late in the series, the location was finally mentioned, being called Hillwood City, in Washington state.

The series was cancelled in 2004 with the last episode "The Journal" teasing viewers into an eventual movie where Arnold finds his parents which never got off the ground, but 15 years and millions of letters later Hey Arnold!: The Jungle Movie premiered on Nickelodeon and finally gave fans the proper send off with Arnold reuniting with his parents, giving us his last name which is Shortman and the icing on the cake, Arnold knowing about Helga's love for him.