It’s a craze that has left billions of sane people baffled and has resulted in scores of victims being scared out of their wits.
The UK has been invaded by an army of clowns who are stalking the streets and terrorising children and adults with knives.
In Northern Ireland police have issued a warning over the craze sweeping the Province.
The warning comes after reports a school in Coleraine closed its doors due to fears people dressed as clowns were on their way.
The so-called “killer clown” craze appears to have been inspired by terrifying pranks in South Carolina, where police first received reports of clowns lurking near launderettes and trying to lure children into the woods.
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It is unclear what sparked the craze, although some claim it may be part of a horror movie publicity stunt or an elaborate hoax.
Since then, clowns have sparked thousands of copycats across the US and worldwide, with police in Australia also issuing stern warnings to would-be clowns.
The craze has also angered professional clowns, who work in circuses and as children’s entertainers, and who have told the i newspaper that the “idiots” are bringing the “art of clowning” into disrepute.
“It’s incredibly frustrating,” said Rob Bowker, a spokesman for Clowns International, the world’s oldest clown club.
“These people are not clowns. They are just idiots wearing clown costume. It isn’t funny.”
Mr Bowker, who works under the name Bibbledy Bob, added: “Clowning is an art form and it takes years to learn. These people are hijacking the costume and scaring people.
”Children have nothing to fear from real clowns. They only want to make people smile. These people are nothing to do with us.“
Clowns have been around for thousands of years – dating back to the court jesters of Henry VIII and beyond – and were traditionally a vehicle for satire.
The word ”clown“ first appeared when Shakespeare used it to describe foolish characters in his plays.
The now familiar circus clown has its origins in the 19th century.
Ann Featherstone, a research fellow in drama at the University of Manchester and an expert in Victorian clowns, told i: ”There is a darker side. There have been nasty clowns throughout history.
“There has always been a suspicion about clowns. It’s to do with the grotesque mask and the make up, which emphasises the nose and the mouth and has no expression. We don’t know what clowns are thinking or what they will do next.”
Professional clowns say the “demonisation” of clowns started in the 1980s, when authors and Hollywood movie directors began depicting them as villains in horror stories.
Perhaps the most feared of all fictional clowns is Pennywise, the red haired clown with razor-sharp teeth, who appeared in Stephen King’s 1986 novel It and which was adapted for television in 1990.
One professional clown told i that the irrational fear of clowns – officially known as coulrophobia – originates from this period and is less seen in today’s children who have not been brought up with these movies.
“In many ways, clowns combine a perfect storm of freaky things,” said Professor Frank McAndrew, a psychologist at Knox College in Illinois, who has carried out the first empirical study of creepiness
Speaking to i from the US, he said: “You cannot tell what they really are or what they are really feeling, and they have an association with serial killers in real life and in the movies.”
He added: “The killer clown has the perfect ingredients for an urban legend. They can occur anywhere and there probably enough copycats keep it going."
The killer clowns show no sign of being vanquished quickly, with shops now selling clown masks for Hallowe’en.