The modern stock character of the evil clown was popularized by Stephen King's novel It, published in 1986, which became the first to introduce the fear of an evil clown to a modern audience. Another one of the first appearances of the concept is that of John Wayne Gacy, an American serial killer and rapist arrested in 1978, who became known as the Killer Clown after it was discovered he had performed as Pogo the Clown at children's parties and other events; however, Gacy did not actually commit his crimes while wearing his clown costume.
Phantom clowns
The related urban legend of evil clown sightings in real life is known as "phantom clowns". First reported in 1981 in Brookline, Massachusetts, children said that men dressed up as clowns had attempted to lure them into a van. The panic spread throughout the US in the Midwest and Northeast. It resurfaced in 1985 in Phoenix, Arizona; in 1991 in West Orange, New Jersey; and 1995 in Honduras. Later sightings included Chicago, Illinois, in 2008. Explanations for the phenomenon have ranged from Stephen King's book It and the crimes of serial killer John Wayne Gacy, to a moral panic influenced by contemporaneous fears of Satanic ritual abuse.
In recent years, the "evil clown" phenomenon has been trending and growing. While most of these clown sightings have been harmless, there have been suspicion activities and others have been led to attacks and arrest. In 2013, the Northampton Clown appeared on the scene terrorizing the town. He shares similar looks to Pennywise the Dancing Clown from Stephen King's book, It. Although rumors said that the clown may have a knife, the clown himself denied these rumors through social media.
In 2014, the phenomenon moved to the United States, when the Wasco clown showed up in social media in California. Again this clown would shared similar resemblance to Pennywise. During an interview with the Wasco clown, it was revealed that the social media postings are part of a year-long photography project conducted by his wife. While the original Wasco clown was merely a project and for fun, other copycats also started appear and in some cases with weapons.
In 2015, starting in the summer, clown sightings began to appear again. In late July, a "creepy" clown was seen around a local cemetery in Chicago and terrorizing anyone in the graveyard.
This must be inspired by the great popularity of the tv series "The Walking Dead". Lots of fans in the UK it seems. 
