Stephen Hillenburg the creater of SpongeBob SquarePants has died at the age of 57.
The news was confirmed by Nickelodeon, which has broadcast the hugely popular cartoon series since 1999.
In a statement, the company said Hillenburg's cause of death was motor neurone disease Amyotrophic Lateral Sclerosis (ALS)- a condition he revealed he had been diagnosed with in March last year.
As well as creating the character, Hillenburg also directed 2004's The SpongeBob SquarePants Movie.
SpongeBob SquarePants began in 1999 and has seen more than 200 episodes broadcast.
It has also been made into a Broadway musical, which won a Tony Award earlier this year.