This is just stupid. It sounds like the guy might have a legit argument, but come on... you don't sue 8 years after it was created. That makes this look like the guy is just out to get money. He probably is. He "found out" about SpongeBob in 2002. So, what, he was like the last guy on earth to hear about him? So he goes for 3 years without knowing SpongeBob, yet thinks that his sponge was popular enough that it was reipped off? Please.
Then he waits another 5 years to sue? Yeah, after you find out the show is worth so much. I doubt this would have happened if it wasn't so successful. And another example of him not really knowing what's going on, which was already mentioned. SpongeBob is certainly not unemployed. And it'd be hard to find further resemblance; it's not like SpongeBob has a wife and kids.
Again, this guy could have an honest claim... but I think he really messed up in the way he waited so long and has shown his lack of knowledge regarding the whole show. That certainly won't help him.