SpongeBob SquarePants is an American animated television series created by marine biologist and animator Stephen Hillenburg for Nickelodeon. The series is set in the fictional underwater city of Bikini Bottom, and centers on the adventures and endeavors of SpongeBob SquarePants, an over-optimistic sea sponge that annoys other characters. Many of the ideas for the show originated in an unpublished, educational comic book titled The Intertidal Zone, which Hillenburg created in the mid-1980s. He began developing SpongeBob SquarePants into a television series in 1996 upon the cancellation of Rocko's Modern Life, another Nickelodeon television series which Hillenburg previously directed.