Here’s the difference a K makes: Around Y1K, roughly 1000 A.D., people trembled as invaders with strange-sounding names swept in from nowhere, took their wealth and made off with their children. Now, here we are, a whole millennium later—and look what’s happening. A wave of invaders with funny names—Pikachu, Snorlax and Charizard—has appeared seemingly out of nowhere, ensnaring 4-to 12-year-olds and forcing bewildered parents to dig deep into their pockets. The Pokémon tsunami, first sighted in Japan in 1996, has become a worldwide phenomenon, submerging Beanie Babies, Furbys and all that came before while amassing $6 billion in sales, $1 billion of that in the U.S., for the Nintendo Corp. and its lucky licensees (which include Time Warner, PEOPLE’S corporate parent). Kids avidly collect the cards and just as avidly trade them with their friends. They flock to see Pokémon: The First Movie, which opened Nov. 10 and has done more than $80 million in business. They wake up to The WB’s 7 a.m. Pokémon cartoon. There are Pokemon T-shirts, video games and accessories (one of the hottest, most hard-to-find items this holiday season: the Pokédex, a sort of Filofax for the ‘ “Pokécentric). Is all this good for kids? The experts, as always, are divided. Many school districts, concerned that kids spend too much time with their Pokémon (the name is a blend of the words “pocket” and “monster”), have banned the cards from schoolrooms and playgrounds. Psychologists such as Dr. Joyce Brothers, however, praise the phenomenon’s values. “The whole point is that you are trying to save somebody, train them, feel responsibility and compassion,” she says. The best tactic for parents seems to be one of benign bafflement. They will never learn the secret language of Pokémon fans—nor do they need to. And already, somewhere over the horizon, a new force is gathering steam. It may even be here for Y2K+1.