SpongeBob SquarePants (born July 14, 1986; age 31) is the main protagonist and the eponymous character of the Nickelodeon animated comedy series of the same name. He was designed by marine biologist and animator Stephen Hillenburg, and is voiced by Tom Kenny. SpongeBob is a childish, joyful, eccentric sea sponge who lives in a pineapple in the underwater city of Bikini Bottom. He works as a fry cook at the Krusty Krab, a job in which he is exceptionally skilled. SpongeBob lacks a lot of knowledge and is a constant annoyance to those around him (especially his co-worker and neighbor, Squidward Tentacles), but he is very good-natured. He appears in all of the episodes in the series, except for "The Algae's Always Greener," in which his alternate-universe counterpart appears instead. He was soon to be Nickelodeon's main mascot.
SpongeBob is a clueless, abnormal, immature, fun-loving, and hyperactive character with a happy-go-lucky personality. He is an extremely determined person, and will often stop at nothing to accomplish a task. He is also somewhat dramatic to the people who are kind to him: for example, to the mailfish.  He is also over-confident. Sometimes, though, he shows his devious side when trying to get Mr. Krabs and Plankton to work together. He sometimes tends to make mountains out of molehills, such as losing his nametag.
SpongeBob is very kind-hearted and innocent, and very rarely acts openly mean to anyone, even his enemies. He is a very selfless and loyal person, especially towards those close to him. His selfless nature is most notably shown in "Best Day Ever," where he sacrifices his "perfect day" to help his friends. Despite his well-meaning intentions, SpongeBob's actions often annoy and cause trouble for those around him, most notably his next-door neighbor, Squidward Tentacles.
SpongeBob can become scared easily and usually panics when frightened. He is afraid of the dark (or what is in the dark) and clowns . He also hates hot sauce. Occasionally, SpongeBob is too ignorant to notice impending danger and his unworldly thinking may put himself or others in peril. He also cannot detect lies or malice information as easy as the other characters, mainly due to his naive nature.
SpongeBob's innocence also makes him overly trusting and very gullible, and he is easily manipulated by people who intend to use and/or harm him, such as Squidward, Mr. Krabs, and Plankton; most noticeably, he is always easily fooled by Plankton no matter how bizarre or obvious his disguises are. Even though he is generally good-natured and easygoing, when frustrated and angered, SpongeBob can be sarcastic, rude, and 'foul-mouthed' to his friends, even Mr. Krabs, whom he treats as a father figure. Ironically, Squidward is the only character whom SpongeBob never insults when he is angry, with the exception of the episodes "Can You Spare a Dime?" and "Breath of Fresh Squidward."
Although SpongeBob has several friends, and many of the citizens of Bikini Bottom often treat him quite friendly, most, if not all, citizens of the city have been shown to have some degree of dislike for him. In the episode "Gone," it is shown that a holiday called "National No SpongeBob Day" has been started by the citizens of Bikini Bottom. As its name suggests, it is an entire day dedicated to getting away from SpongeBob, where the people leave Bikini Bottom for the day. Even Patrick goes, stating that everyone needs at least one day away from SpongeBob's laughter. In the ceremony, they build a giant wooden effigy of SpongeBob, burn it down, dance on the ashes (though some, like Squidward, are actually shown kicking the ashes), and depart Bikini Bottom. SpongeBob is more honored than insulted by this, as he was the "inspiration" for the holiday
Like many other cartoon characters, SpongeBob has been shown to have numerous extraordinary abilities and attributes over the course of the series (even though physically weak).
- Soft Pliable Body: Due to his soft, pliable frame, he is capable of shape shifting, has some degree of invulnerability, being able to absorb any type of physical impact, shown most notably in the episode "The Bully."
- Regeneration: It is shown that he can quickly regenerate parts of his body that are injured or removed.
- Boneless: SpongeBob is usually shown to be boneless (sea sponges being invertebrates), however in some episodes such as "I Had an Accident," bones are shown on his X-rays. He also has bones when he rips his skin off in "Atlantis SquarePantis," and "The Splinter."
- Absorbent: Being a sponge, he is also absorbent, and can expand his body by absorbing liquids. When he cries, he often re-absorbs his tears. An example being in "The Bully" when Flats the Flounder kept on hitting him, but SpongeBob just absorbed all of his blows. Also, in "I Had An Accident," he filter fed through his holes as he is a sponge.
- Singing and Nose Playing: SpongeBob is shown to possess a fantastic singing voice. He uses his nose as a flute, in which he is very good. He was also the lead singer in "Band Geeks." Later, he uses his nose flute in "Best Day Ever" to drive away the Nematodes from the Krusty Krab.
- Fry Cooking: SpongeBob has a job cooking Krabby Patties at the Krusty Krab.
- Jellyfishing: SpongeBob and Patrick jellyfish in several episodes, in "Jellyfish Hunter"; he catches every single jellyfish in the fields.
- Tongue Boarding: SpongeBob tongue-boarded in "Pre-Hibernation Week," he can also do it in the Battle for Bikini Bottom video game.
- Survival Skills: In "To Save a Squirrel," SpongeBob and Patrick almost ate each other to survive.
- Bubble Blowing: SpongeBob can perform extraordinary moves with bubbles.
- Driving: He drives perfectly in various episodes, but drives recklessly on other episodes, which are in the appearances of Mrs. Puff.
- Karate: He trains in Karate perfectly, and rarely mixes them up.
- Destruction: Although, he does not know it and thanks to his poor driving skills, SpongeBob is actually skilled at Demolition Derbies. This was shown in "Demolition Doofus" as SpongeBob (who was using the name Le Squish) managed to defeat five other competitors (also surviving against Mrs. Puff).