'SpongeBob SquarePants' creator Stephen Hillenburg's career spanned cartoons, marine biology

Stephen Hillenburg created nautical nonsense under the sea.

The "SpongeBob Squarepants" creator passed away Monday at the age of 57 following a battle with Lou Gehrig's disease, also known as ALS.

"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," Nickelodeon said in a statement. "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."

Before becoming a cartoonist, Hillenburg was on an entirely different career path as a marine biology teacher. His experiences in this field served as the catalyst for some of the wildly popular "SpongeBob" characters.

Hillenburg earned a degree in experimental animation from the California Institute of Arts and had a Master of Fine Arts, as well.

Read on for a look at his career.

'SpongeBob SquarePants'

Hillenburg conceived, wrote, produced and directed "SpongeBob SquarePants," the animated series that began in 1999 and went on to spawn hundreds of episodes, movies and a Broadway show as it accumulated a cult-like following.

"SpongeBob" won numerous awards throughout the years, including several Annie and Daytime Emmy awards.

"I thought we’d get four seasons, but it’s still going," he told The Guardian in 2016. "I see 'SpongeBob' on ice-cream trucks a lot and I’ve got bootleg 'SpongeBob' merchandise from Mexico. In Egypt, they even wear hijabs with 'SpongeBob' on them."

'Rugrats'

From 1997 to 1998, Hillenburg was a writer for Nickelodeon's "Rugrats," according to his IMDB page.

'Rocko's Modern Life'

Hillenburg worked as a director and writer for Nickelodeon's "Rocko's Modern Life" from 1993 to 1996, according to his IMDB page.

'Wormholes'

Hillenburg won the Best Animated Concept at the Ottaway International Animation Festival for his short "Wormholes" in 1992, Variety reported. This was the year he earned his Master of Fine Arts.

He also created the "Green Beret" in 1992. This animated movie featured a Girl Scout who struggled to sell cookies because she had exceptionally large hands.

Marine Biology

Before becoming a cartoonist, Hillenburg taught marine biology at what is now the Ocean Institute in California. This experience led to some of his cartoon creations for "SpongeBob," according to Variety.

He told The Guardian he was "great at art and so-so at marine biology."

"It’s funny how the two eventually came together," Hillenburg said.

Fox News' Sasha Savitsky and The Associated Press contributed to this report.