Stephen Hillenburg, creator of the Nickelodeon cartoon show “Spongebob Squarepants” passed away on Monday, at age 57. Stephen told the public last year that he had been diagnosed with neurodegenerative disease ALS, or Lou Gehrig’s disease. ALS, is a progressive neurodegenerative disease that affects nerve cells in the brain and the spinal cord.

“We are incredibly saddened by the news that Steve Hillenburg has passed away following a battle with ALS,” Nickelodeon said. “He 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.”