He has, however, been involved in a controversy with some conservative social groups for allegedly promoting homosexuality, although Hillenburg has described the character as biologically asexual (as real-life sea sponges are). The character has garnered a positive response from media critics and is frequently named as one of the greatest cartoon characters of all time. SpongeBob SquarePants has become popular among children and adults. SpongeBob's first appearance was in the pilot, ' Help Wanted', which premiered on May 1, 1999. Hillenburg began developing a show based on the premise shortly after the 1996 cancellation of Rocko's Modern Life, which Hillenburg directed. He drew the book while teaching marine biology to visitors of the Ocean Institute during the 1980s. The character's name is derived from 'Bob the Sponge', the host of Hillenburg's unpublished educational book The Intertidal Zone. SpongeBob was created and designed by Stephen Hillenburg, an artist and marine science educator. He is voiced by actor and comedian Tom Kenny. He is characterized by his optimism and childlike attitude, and is influenced by other comedic characters, including Stan Laurel and Pee-Wee Herman. SpongeBob SquarePants is the title character and protagonist of the American animated television series of the same name.