The King of the Hill will be deposed, The Simpsons will look cuddly and Beavis and Butthead like extras from Grange Hill - because South Park is coming.
South Park is the sickest, weirdest and funniest adult cartoon the Americans have yet produced and complete with talking turds, dead kids and religious persecution, it is coming to Channel 4 this spring.
South Park is the name of the tiny Colorado town that is home to four spherical-headed eight year-olds: Kyle, Kenny, Cartman and Stan.
The animation is atrocious but it is the storylines that will outrage The Daily Mail and make the show the twisted Teletubbies of 1998.
In the first episode Cartman, the fat kid, is abducted by aliens who jab him with anal probes and mutilate cattle. But Cartman deserves it, he is the child of a single mother who spoils him terribly and he is a dumb, arrogant, anti-Semite.
Equally disturbed is Kenny. Kenny is the poor kid with the permanently zipped-up hood. He has had a screwy childhood and is over-familiar with what the producers call "adult" issues. Kenny drinks petrol and in a popular theme of the show gets killed or hideously maimed each week in bizarre accidents.
Other running gags include the boys' debate about whether to help Stan's 103-year-old grandfather kill himself and whether they should go hunting with Vietnam vets who use hand grenades when fishing and anti-aircraft missiles to obliterate deer.
The only smart kid is Kyle, who is Jewish, but as the only Jewish kid in town he doesn't really know what it means except that he doesn't get to celebrate Christmas. In the most controversial episode so far shown in America he sings about being a "lonely Jew" at Christmas: "I'm a Jew, a lonely Jew, at Christmas/I'd sing Carols but I'm Hebrew, at Christmas".
Because of his friends' teasing Kyle creates an imaginary friend in Mr Hanky, a talking poo who comes up out of the toilet to give presents to children with a high-fibre diet. After taking his talking poo to school, Kyle ends up in an asylum.
All of which makes South Park sound like a succession of toilet jokes. In PC-weary America the show has become a cult hit - getting the top ratings on cable TV at Christmas, and in Canada it is already a top ten show even though it has to be aired at midnight.
But like The Simpsons, underneath the jokes South Park is in fact a sophisticated critique of dysfunctional America. The kids fall for hyperbolic advertising, they see UFOs and are told they are pigeons by the town's very own government cover-up expert, their teacher talks to them through a glove puppet - Mr Hat - who has a psychotic mind of his own.
And the way South Park came into being is as contemporary a tale of America as you are likely to get. It started off as a five-minute college project called The Spirit of Christmas by its two creators Matt Stone, 26, and Trey Parker, 28.
The short film was seen by a television executive who had 40 copies of the cartoon made to send to friends as video Christmas-cards - which is the kind of thing TV executives do to impress in America. This made it an underground hit in Hollywood and a bidding war ensued to sign up Stone and Parker.
Parker says they had a cunning test when choosing a TV company to go with: "When we were first getting courted by all the networks I used to say: `One thing I really need to know before we go any further. How do you feel about talking poo?'"
The Spirit of Christmas had Jesus coming to South Park to battle it out with Santa Claus over the true meaning of Christmas - presents or religion. When Christ tries to get the kids to help him their loyalties are divided because after all, Santa gives them presents and Kyle doesn't even believe in Jesus.
From Hollywood, The Spirit of Christmas then ended up on the Internet, where it became a word of mouth hit as it was downloaded on college campuses and in offices around the country. People across America were using up fantastic amounts of computer memory e-mailing the five-minute cartoon to friends.
All of which meant that by the time cable company Comedy Central aired the first made-for-TV episode of South Park in August it was a guaranteed smash. The T-shirts and merchandise immediately started selling out and the first programme got more pre-publicity than any show in the station's history. Celebrities like Robert Smith of The Cure are already queuing up to do voice-overs for the cartoon characters.
"Robert Smith said to me he thought it was going to be huge in England," says Trey Parker. "Because he thought it was a very British sense of humour. Which makes sense because Matt and I were both huge Monty Python fans. That is undoubtedly where our sense of humour comes from."
That sense of humour is now coming home to roost and you can expect to see the Mr Hanky T-shirts sweeping Britain by the summer.