Well, I'll be an absorbent invertebrate. Has it really been 10 years since we first met a happy little cartoon sponge that lives in a pineapple under the sea?

You'd better believe it. "SpongeBob SquarePants" celebrates a decade of underwater delirium this month, and Nickelodeon is making a big splash to celebrate with a "SpongeBob" documentary and weekend?marathon.

The fun starts at 8 p.m. Tuesday on VH1 with "Square Roots: The Story of SpongeBob SquarePants," a star-studded original documentary that chronicles the animated life of the boxy yellow dude. SpongeBob mania then kicks into high gear with a 50-hour marathon of classic and new episodes running Friday night through Sunday.

For "SpongeBob" executive producer Paul Tibbitt, 10 years of "SpongeBob" is a lot to soak in.

"I got a feeling early on that it would at least be good, a good cartoon," he says. "As far as being on for 10 years and all the other stuff that comes along with it? No idea. I don't think anyone really knows when that's going to happen."

"SpongeBob" creator Stephen Hillenburg developed the character back in the '80s to amuse kids at the Orange County Marine Institute in California. The former marine biologist gave those doodles new life when "SpongeBob SquarePants" debuted July 17, 1999. Tibbitt has been with the show from the beginning, first as a writer and director and now as executive producer.

"Steve had a really solid idea of what he was doing before he even madeww the pilot," Tibbitt says. "I think still to this day, this many seasons in, we're finding new channels of humor for SpongeBob."

That humor is as innocent and earnest as it is manic and quirky.

Broad appeal

Tibbitt says SpongeBob is up for anything and tries to find the bright side in every situation — good intentions that naturally result in wackiness for him and fellow Bikini Bottom cohorts Patrick (a dim-bulb starfish and SpongeBob's best friend), Sandy Cheeks (a sassy squirrel in an astronautlike outfit), Squidward (a grouchy squid) and Mr. Krabs (a penny-pinching crab).

"We knew we were making a cartoon for Nickelodeon, which is mainly watched by chileren," Tibbitt says, "but we never really set out to pander or talk down to kids. ... Luckily there were some adults paying attention while the kids were watching."

That cross-generational fan base speaks volumes with its remote controls as well as with its wallets.

Solid ratings