Dancers wearing new bikinis perform in front of passers-by and a line of photographers during a promotional flash mob event on a square outside Shinjuku station in Tokyo on July 18, 2016. The event was organized by the Japan Swimsuit Association to promote new swimwear. (Photo by Toru Yamanaka/AFP Photo)

A competitor shouts as he takes part in the “Tough Guy” adventure race near Wolverhampton, central England, on January 29, 2017. The Tough Guy event, which is being held for the final time in its 30th year, challenges thousands of competitors to run a gruelling course whilst negotiating over 200 obstacles including: water, fire, and tunnels. (Photo by Oli Scarff/AFP Photo)

An ethnic Armenian fighter carries Kalashnikov machine guns to his comrade-in-arms at Martakert province in the separatist region of Nagorno-Karabakh, Azerbaijan, Monday, April 4, 2016. (Photo by Vahan Stepanyan/PAN Photo via AP Photo)

Iranian Shiite Muslim women gather around a bonfire after rubbing mud on their body during the “Kharrah Mali” (Mud Rubbing) ritual to mark the Ashura religious ceremony in the city of Khorramabad, some 470 kms southwest of Tehran, early in the morning on October 1, 2017. “Khrreh Mali” or “Mud Rubbing” is a ritual that is held in the city of Khorramabad every year to commemorate the seventh century slaying of Prophet Mohammed' s grandson Imam Hussein, in which Iranian men roll over in mud and dry themselves by gathering around the bonfires before flagellating themselves. (Photo by Atta Kenare/AFP Photo)

A young woman dressed as a zombie takes part in a zombie parade as part of the Brussels International Fantastic Film Festival 2014 in Brussels, Belgium, 12 April 2014. More than a hundred of participants took to the streets of Brussels. (Photo by Ulien Warnand/EPA)

Soccer player David Beckham (C) with Cruz Beckham (L) and Romeo Beckham (R) get slimed onstage during Nickelodeon Kids' Choice Sports Awards 2014 at UCLA's Pauley Pavilion on July 17, 2014 in Los Angeles, California. (Photo by Kevin Winter/Getty Images)

Collided passenger train cars are seen in Taebaek, South Korea, Tuesday, July 22, 2014. Two passenger trains collided head-on in eastern South Korea on Tuesday afternoon, killing one passenger and injuring dozens, fire officials said. (Photo by AFP Photo/Yonhap)