The creator of SpongeBob SquarePants has died at the age of 57.
Nickelodeon announced on Tuesday that Stephen Hillenburg, the cartoonist and animator responsible for the cult character and its namesake animated series, passed away.
He had announced last year that he had been diagnosed with ALS.
"We are sad to share the news of the passing of Stephen Hillenburg, the creator of SpongeBob SquarePants," the network said in a tweet.
"Today, we are observing a moment of silence to honour his life and work."
Hillenburg, a former marine biologist, grew up fascinated by the ocean.
He was a fan of French oceanographer Jacques Cousteau as a child and once told The Guardian he first went scuba-diving aged 14, which "blew his mind".
"It was all colour, another world," he told the publication in 2016.
"I studied natural resources planning and thought I could get a job at some marine park.
"But I was great at art and so-so at marine biology. It’s funny how the two eventually came together."
Hillenburg got his start at Nickelodeon as a director for the animated series Rocko's Modern Life. He thought up a talking sponge character, which eventually turned into SpongeBob.
From there, Hillenburg imaged the now-famous universe that makes up SpongeBob's life in the underwater town of Bikini Bottom, from his loyal best friend Patrick to his fast food job at the Krusty Krab
Nickelodeon further paid tribute to Hillenburgh in a statement to the Reuters news agency.
"We are incredibly saddened by the news that Steve Hillenburg has passed away following a battle with ALS," the network said.
"He was a beloved friend and long-time creative partner to everyone at Nickelodeon, and our hearts go out to his entire family."
When Hillenburg first publicly discussed his diagnosis, he told Variety he intended to keep working as long as he would be able to.
He is survived by his wife Karen and their son Clay.
SpongeBob SquarePants, the series, is currently in its 12th season.
Since it first aired in 1999, the series has received six Annie Awards and four Emmy Awards.
The show has turned into an internationally beloved media franchise including two films (and a third one scheduled to come out in 2020), theme park rides, merchandise, video games, and a Broadway adaptation.
