SpongeBob was created by Steve Hillenburg, a former marine biologist and science teacher who went to art school to study cartooning. Like SpongeBob, Hillenburg once worked as a fry cook at a seafood restaurant.
Hillenburg liked drawing marine life and thought sponges were the "oddest of all" these creatures. But the lumpy shape of natural sponges didn't feel right for the character he wanted to create. A sink sponge turned out to be perfect—it's so clean and so square, just like the innocent and un-hip SpongeBob.
SpongeBob lives in a pineapple because pineapples are a common motif in Polynesian crafts. In addition, Hillenburg says he thought SpongeBob "would like the smell" of a pineapple home. Smell is a very important sense for sea animals.
SpongeBob was originally named SpongeBoy. However, that name was already trademarked (legally owned by someone else).
Squidward only has six legs, but he is nevertheless an octopus. Animators thought that having eight legs on the character—which would be correct for an octopus—made him look too burdened.
Tom Kenny, who does the voice of SpongeBob, says his character's laugh was meant to make viewers think of the ocean. It is based on the distinctive call of a dolphin, with just a touch of a seagull's shriek.
Tom Kenny also does the voices of Dog on Catdog and the Mayor of Townsville on The Powerpuff Girls.
According to SpongeBob's driver's license, he was born July 14, 1986. But he was already living on his own—and trying to get a job at the Krusty Krab—when the SpongeBob show debuted in 1999.
The recipe for Krabby Patties is a well-guarded secret, but creator Hillenburg has hinted that these mystery burgers may be vegetarian. Otherwise, some inhabitants of Bikini Bottom would be cannibals.
SpongeBob always tries to do his best. He's now helping out the New York City Department of Environmental Protection by urging kids to help save water. The campaign features an enormous SpongeBob—swollen from absorbing an entire bathtub of water—with the slogan "Save Water—Don't Drip New York Dry!"