Stephen Hillenburg, creator of Nickelodeon's widely beloved animated series, SpongeBob SquarePants, died on Monday (November 26) at the age of 57.

Hillenburg first took viewers into the pineapple under the sea on May 1, 1999, and since then, Nickelodeon has aired 250 SpongeBob episodes around the world and has spawned two movies, a Broadway musical, and multiple video game adaptations.

The award-winning program has received critical acclaim over the years and took home two Daytime Emmys at this year's ceremony, including the prize for Outstanding Children's Animated Program. But most importantly, audiences everywhere truly loved the silly, innocent, pants-wearing sponge and all his Bikini Bottom friends — as did Hillenburg, a former marine biology teacher.

"A sponge is a funny animal to center a show on," he once said. "At first I drew a few natural sponges — amorphous shapes, blobs — which was the correct thing to do biologically as a marine science teacher. Then I drew a square sponge, and it looked so funny. I think as far as cartoon language goes he was easier to recognize. He seemed to fit the character type I was looking for — a somewhat nerdy, squeaky-clean oddball."

Before creating the wildly successful franchise, Hillenburg worked on two other Nickelodeon classics, Rocko's Modern Life and Rugrats. The network mourned the loss in a statement.

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

Said joy will undoubtedly live on, as fans post countless SpongeBob memes in remembrance.