WASHINGTON — Stephen Hillenburg, a onetime marine biology teacher who created the enduringly popular ‘‘SpongeBob SquarePants,’’ an Emmy Award-winning animated Nickelodeon program about a goofy underwater world that was the defining cartoon show of its generation, died Monday at his home near Los Angeles. He was 57.
He had amyotrophic lateral sclerosis, or Lou Gehrig’s disease, said Susan Grode, a lawyer for the family.
Long fascinated by art and cartoons, Mr. Hillenburg turned to animation and in 1999 launched ‘‘SpongeBob’’ on the Nickelodeon network. He wrote, produced, and directed the series, which evolved into movies and a Broadway show.
The series, set underwater at Bikini Bottom, was relentlessly, even absurdly upbeat.
The title character was introduced in the show’s theme song: ‘‘Absorbent and yellow and porous is he!’’ Resembling an ordinary kitchen sponge wearing shorts and a necktie, SpongeBob had big eyes, two teeth, and an oversized pair of shoes.
He lived in a pineapple under the sea with his pet snail, Gary, and was beamingly proud of his job making Krabbie Patties at the Krusty Krab eatery.
SpongeBob was surrounded by a zany cast of anthropomorphic creatures, including a pink starfish named Patrick Star; a squirrel named Sandy Cheeks who adapted to underwater life by living in a dome; Squidward Tentacles, a snobbish, clarinet-playing octopus; the cranky owner of the Krusty Krab, Mr. Krabs; and the diabolical Plankton, a villain constantly plotting to steal the recipe for Krabbie Patties, guarded by SpongeBob.
By replaying endless variations on these characters and themes — including SpongeBob’s futile attempts to obtain a boating license from Mrs. Puff, a puffer fish — the show became a whimsical cultural phenomenon watched by tens of millions of viewers each week.
‘‘It seems to be a refreshing breath from the pre-irony era,’’ Syracuse University pop-culture scholar Robert Thompson told The New York Times in 2001. ‘‘There’s no sense of the elbow-in-rib, tongue-in-cheek aesthetic that so permeates the rest of American culture . . . I think what’s subversive about it is it’s so incredibly naive — deliberately.’’
The program attracted fans among celebrities — Ellen DeGeneres, Bruce Willis, and Jerry Lewis all admired its absurdist humor — and among college students, who reveled in the adult overtones that occasionally floated to the surface from Bikini Bottom.
In 2005, SpongeBob and other cartoon characters were featured in a promotional video promoting tolerance and diversity. Afterward, James Dobson, leader of the conservative activist group Focus on the Family, accused SponeBob and his cartoon pals of being a little fishy.
‘‘Their inclusion of the reference to ‘sexual identity’ within their ‘tolerance pledge’ is not only unnecessary,’’ he said, ‘‘but it crosses a moral line.’’
Mr. Hillenburg replied that tolerance was certainly a theme of the show, but the idea of sexuality had no connection to the innocent characters of ‘‘SpongeBob SquarePants.’’
‘‘I consider them to be almost asexual,’’ he said. ‘‘We’re just trying to be funny and this has got nothing to do with the show.’’
Born at his father’s army post in Lawton, Okla., Mr. Hillenburg graduated from Humboldt State University in California in 1984 with a degree in natural resource planning with an emphasis on marine resources.
He taught marine biology at the Orange County Marine Institute.
While there he drew a comic, ‘‘The Intertidal Zone,’’ that he used as a teaching tool. It featured anthropomorphic ocean creatures that were precursors to the characters on ‘‘SpongeBob.’’
Mr. Hillenburg shifted to drawing and earned a master of fine arts degree in animation from the California Institute of the Arts in 1992.
That same year he created an animated short called ‘‘Wormholes’’ that won festival plaudits and helped land him a job on the Nickelodeon show ‘‘Rocko’s Modern Life,’’ where he worked from 1993 to 1996 before he began to build SpongeBob’s undersea world of Bikini Bottom, which showed off his knowledge of marine life and willingness to throw all the details out the window.
‘‘We know that fish don’t walk,’’ he told the AP, ‘‘and that there is no organized community with roads, where cars are really boats. And if you know much about sponges, you know that living sponges aren’t square.’’
Its nearly 250 episodes have won four Emmy Awards and 15 Kids’ Choice Awards.
In 2004, the show shifted to the big screen with ‘‘The SpongeBob SquarePants Movie’’ and a 2015 sequel, ‘‘The SpongeBob Movie: Sponge Out of Water.’’
Intensely involved in every aspect of the show initially, Mr. Hillenburg after the 2004 film stepped back into an executive producer role on the show, where he remained for the rest of his life.
A musical stage adaptation bowed on Broadway in 2017, with music from such stars as Steven Tyler, Sara Bareilles, and John Legend. It earned 12 Tony Award nominations, including one for best performance by a leading actor for Ethan Slater.
‘‘I am heartbroken to hear of the passing of Stephen Hillenburg,’’ Slater said in an e-mail Tuesday. ‘‘He warmly embraced us on Broadway as the newest members of his wonderful ‘SpongeBob’ family, and made it so clear from the get-go why he is so beloved: genuine kindness.’’
Mr. Hillenburg leaves his wife of 20 years, Karen; a son, Clay; mother, Nancy; and a brother, Brian.
Even though SpongeBob worked as a hamburger cook, Mr. Hillenburg refused to license his image to sell fast food and other products he considered harmful to children. Nonethless, by 2009 Advertising Age magazine estimated that Nickelodeon earned $8 billion a year in sales of SpongeBob merchandise.
‘‘How could you expect a show about a sponge to have mass appeal?’’ he told The Boston Globe in 2002. ‘‘It’s just unbelievable. It’s almost like having a picture of your mother appear on everything in the world.’’
Material from the Associated Press was used in this report.