From Bikini Bottom to A-list celebrity: why the world loves SpongeBob SquarePants is taking over ghghjg ghghg ghg He's yellow, he's square and he's over here: Meet the new cartoon sensation SpongeBob

WHAT IS square, yellow, and adored by under-10s, students and celebrities? The answer is SpongeBob SquarePants, the biggest custard- coloured cartoon sensation to sweep the nation since The Simpsons.

The annoyingly cheerful rectangular sponge who lives in a pineapple at the bottom of the ocean is about to achieve world domination when SpongeBob SquarePants - the Movie opens in cinemas on Friday.

The Oasis lead singer and renowned wildman, Liam Gallagher, along with the hard-edged rapper, Goldie, were among those who turned out to watch the film's premiere this week, showing just how street cred the children's cartoon character has become.

In the US, the tie and trouser-wearing sponge already has a huge celebrity fan base, including Britney Spears, Justin Timberlake, Mike Myers, Bruce Willis and Kelly Osbourne. There is even a church established in his name, with 700 followers who meet in New York, California and Texas.

Next week in the UK, the children's network Nickelodeon is showing back- to-back episodes of the cartoon on its animation channel Nicktoons over half term, in what it is calling a "SpongeBobathon".

SpongeBob, who first appeared on American television in 1999, is the creation of Stephen Hillenburg, a former marine scientist - but the cartoon is anything but scientific.

The aquatic character lives underwater in Bikini Bottom, where he works as a fry cook at the Krusty Krab diner and keeps a pet snail called Gary who miaows like a cat. His best friends are a pink starfish called Patrick and a female squirrel called Sandy Cheeks, who wears a helmet so she can breathe underwater.

In 2004, 9.7million viewers watched SpongeBob on Nickelodeon channels, including two fifths of all children in the UK and it is now the top-rating show on Nicktoons.

The cartoon is a major earner, having made a reported pounds 400m since 2002. A DVD of the show is Nickelodeon's fastest- selling title and there are even SpongeBob computer games on the Playstation's .

The happy-go-lucky character has been signed as the face of an advertising campaign for Volvic flavoured spring water, and sponsors of the television show have included the Scottish sweets brand Millions, and Bell's Cheese Dippers.

While it was originally targeted at seven-to-nine year olds, SpongeBob's appeal is growing among adults who appreciate the cartoon's surreal humour.

The Radio 1 breakfast DJ, Chris Moyles, as well as Capital Radio's Johnny Vaughan and Xfm's Christian O'Connell are all devotees. O'Connell described the show as: "A cartoon made by Tarantino and drawn by Rolf Harris after one too many beers."

Howard Litton, Nickelodeon's director of channels, said: "There seems to have been a groundswell over the past 12 months. In some ways it's like The Simpsons when it first launched. Although it's targeted at kids, it's become popular with adults and it's cool in student circles. It's got huge support because of its quirkiness and its silliness. People buy into the optimism of SpongeBob."

In the US, however, right-wing Christian groups have tried to uncover a darker side to Spongebob, accusing the cartoon's creators of promoting homosexuality to children.

A row broke out over Spongebob's involvement in a remake of the Sister Sledge song "We Are Family", which Christian activists claim is pro-gay propaganda.

The organisers of the music video, which also features Bob the Builder, Winnie the Pooh and Rugrats, deny that it contains a subliminal message and insist that it is intended to help teach children about co-operation and unity. But rumours persist that SpongeBob is a gay icon because he holds hands with his sidekick Patrick.

The controversy is similar to the whispering campaign in 1999 about Tinky- Winky, a character in the pre-school programme Teletubbies, who carried a handbag, but Mr Litton is sceptical.

"I think they were on to something with Tinky-Winky, but this is insane. You can find anything in anything if you look hard enough."