Character Name: SpongeBob SquarePants
Location: Pineapple home on 124 Conch St., Bikini Bottom (to the right of Squidward's house)
Occupation: Frycook at the Krusty Krab restaurant
Interests: Jellyfishing, blowing bubbles, cooking and eating Krabby Patties, Mermaidman and Barnacleboy, hanging out at Goo Lagoon, sandboarding, karate
Personality: Happy, playful, loud, caring
Physical Appearance: Yellow, rectangular, blue eyes, buck teeth, square pants, tie, white shirt, black shoes
Family: Mother, father, grandmother, Uncle Sherm, Uncle Captain Blue, Blackjack (cousin), grandfather, Junior the scalop (adopted by SpongeBob), Gary, SpongeGar (ancestor), SpongeBuck (ancestor)
Friends: Patrick, Sandy, Gary, Larry, Squidward (but SpongeBob isn't a friend to Squidward)
First Episode Appearance: "Help Wanted"
Voiced By: Tom Kenny
Other Info: Convinced Squidward's band to shape up after they all turned away from him. Retreived King Neptune's crown by traveling to Shell City, and spared Mr. Krabs's life by doing so. Defeated King Neptune in a frycooking contest. Accepted by the Jellyspotters. Sold lots of chocolate to Tom and received enough money to rent out the Fancy restaurant for a night. Won Employee of the Month at the Krusty Krab 26 months in a row. Prevented Plankton from placing Krabby Patty into analyzer by talking about how wonderful the burger is. Won the hearts of his audience at the Krusty Krab's talent show by mopping the stage. Destroyed Plankton's Mr. Krabs robot by placing a penny in a "1 cent self destruct" slot. Inflated his pants to fly through Bikini Bottom. Drove Plankton insane by refusing to make him a Krabby Patty. Finished boating school essay minutes before it was supposidly due. Prevented evil doodle of himself from destroying him. Brought Mermaidman and Barnacleboy out of retirement. Caught a sickness called "suds." Visited the dreams of townspeople. Became "normal" for a short time. Almost went crazy when he was all alone on "No SpongeBob Week." Became afraid of Krabby Patties due to being sleep-deprived. Attended Mr. Krabs's Navy reunion disguised as him. Worked shortly as a reporter for Mr. Krabs' newspaper. Got amnesia and wondered away from Bikini Bottom, becoming mayor of New Kelp City. Became very wealthy for a short time after finding a special pearl in a clam. Threw the whole town in jail while masquerading as Mermaidman. Rode the Big One (a huge wave) with Patrick, Squidward and Mr. Krabs.
SpongeBob has appeared in every episode so far (obviously). He's the only character to have done so.