SpongeBob SquarePants is a chipper sea sponge and the titular character and protagonist of the show with the same name. He is shown to be a kind, funny, fun-loving, and happy go-lucky character. He looks like a cleaning sponge instead of an actual sea sponge. He first appeared in the pilot episode that aired in May 1999, "Help Wanted."
Since SpongeBob is a main character and the titular character, it means he appears in almost every episode. Though it also appears that ever since the seasons that came after the first movie his voice has gotten a bit higher then when from he had a more deeper voice in the first three seasons.
SpongeBob's best friend is known to be Patrick Star the dim-witted pink star fish who appeared to have gotten dumber through the seasons, in other words as the series progresses Patrick has gotten dumber. SpongeBob though as well appears to have gotten more dumber as the series progresses, such as in one episode he finds out where boogers came from.
SpongeBob also has his pet snail, Gary the Snail, who is equivalent to a cat in our world.
He appears in every episode to date, but has minor and secondary roles in some episodes.
SpongeBob is a yellow sea sponge that looks like a cleaning sponge. He is a yellow sea sponge with olive green holes around his body. He usaully wears a white shirt with a red tie and brown pants that over-lap his shirt and a black belt that goes around the pants. He also wears socks with red & blue stripes (3 stripes on each sock). SpongeBob also wears black shoes, but while working at the Krusty Krab wears a hat whith a dark blue anchor.
His parents look like real sponges but he looks more like a cleaning sponge.
SpongeBob is considered to be both sexual and asexual.
His name was originally going to be SpongeBoy, but the name was used by a cleaning company. Hillenburg wanted to have "Sponge" in his name so people won't mistake him for a "Cheese Head". So he used SpongeBob. He chose "SquarePants" for the last name, as it had "a nice ring to it."