‘SpongeBob SquarePants’ creator Stephen Hillenburg has died at the age of 57.

Stephen’s cause of death was ALS, also known as motor neurone disease, which he was diagnosed with last year.

In an official statement, a spokesperson for Nickelodeon – the network on which his cartoon creation first became a huge hit – said they were “incredibly saddened by the news”.

The statement read: “[Steve] was a beloved friend and long-time creative partner to everyone at Nickelodeon, and our hearts go out to his entire family.

“Steve imbued SpongeBob SquarePants with a unique sense of humor and innocence that has brought joy to generations of kids and families everywhere. His utterly original characters and the world of Bikini Bottom will long stand as a reminder of the value of optimism, friendship and the limitless power of imagination.”

Stephen began his career in animation on the Nickelodeon show ‘Rocko’s Modern Life’, where he stayed for three years.

‘SpongeBob SquarePants’ eventually aired in the US for the first time in May 1999, and quickly became a huge hit all over the world, eventually leading to two spin-off films, the second of which debuted in 2015.

The show tells the story of the titular sponge, voiced by Tom Kenny, who lives, as revealed in the show’s iconic opening song, “under the sea”, along with his friends Patrick Star and Squidward.

‘SpongeBob’ became hugely popular thanks to its irreverent sense of humour and optimistic tone, with a musical production opening on Broadway last year, to rave reviews.