If Horatio Alger were alive today, he'd be eating his well-starched shorts, man. Never has a young upstart—a nonhuman one, at that!—attained so much doing so little. Think of Bart Simpson as this year's king of the un-liners: unambitious, unmanncred, uncooperative and the new poster child for underachievers. At 10½, he is, however, anything but unsuccessful. During 1990 Bart T-shirts (broadcasting such trademark Bartisms as DON'T HAVE A COW, MAN!) were selling at a clip of 1 million a day. (This rattled some teachers, who banned the shirts.) Then there are the baseball hats, bumper stickers, even an air freshener. And an Emmy for animated series (the family even turned up, Roger Rabbit fashion, as presenters). Unbelievable!

"The phenomenon has gone beyond my wildest dreams—and my wildest nightmares," says the Simpsons' creator, Matt Groening, 36, who first sketched Bart in 1987. Last winter Bart and clan emerged in a Sunday-night series that sassed its way into the Nielsen Top 10 and made Bart an instant antiestablishmentarian sensation.

This season Bart moved to Thursdays and went eyeball-to-eyeball with that paragon of goodness Bill Cosby. The Simpsons have been losing that ratings battle. But, even if his creator is a bit unhappy ("We didn't volunteer for this move," Groening has said), Bart remains an undiminished smash. "He has latched onto a secret that kids respect," says Groening. "The entire world of grown-ups is corrupt and stupid." Within a year, that entire world can have a cow: The show will air in, among other civilized nations, France, Mexico, Sweden, Yugoslavia, Australia and the Philippines. "If we're lucky," Groening says, "the world will enter an era of immense underachieving." Can you say "Ay, caramba!" in Swedish?