"'SpongeBob SquarePants' is the unlikeliest of cartoon heroes--or marketing icons," wrote USA Today's Gary Strauss of the Nickelodeon Network's surprise mega-hit. Strauss noted the "oddball name," as well as the "buckteeth [and] spindly arms" of the lead character, a sponge who lives on the sea floor at Bikini Bottom. And he is not just any sponge, but a square yellow sponge that looks like it's come fresh from a supermarket rather than the ocean bottom. Strauss and others have likened this hero to a talking "Swiss cheese." Something of a nerd, SpongeBob lives in a pineapple, has a pet snail named Gary, an irascible neighbor named Squidward, a squirrel girlfriend, a starfish buddy, and a job as a fry cook at the Krusty Krab. The good-natured SpongeBob perennially gets himself and others in trouble. And his sunny-faced optimism just as regularly saves him.

The brainchild...