A South Korean soldier wear North Korea's military uniform, acting as North Korean soldier during an anti-terror and anti-chemical drill session held as part of the 2011 Ulchi Freedom Guardian (UFG) event on August 17, 2011 in Seoul, South Korea. The 11-day UGC, which features drills including the handling of chemical and biological attacks, is a regular joint exercise between US and South Korean troops to prepare for potential emergencies on the Korean Peninsula. (Photo by Chung Sung-Jun/Getty Images)

Festival goers plays in mud during the 15th Annual Boryeong Mud Festival at Daecheon beach in Boryeong, about 190 km (118 miles) southwest of Seoul, July 15, 2012. About 2 to 3 million domestic and international tourists visit the beach during the annual mud festival, according to the festival organisation. (Photo by Chung Sung-Jun)

A hen, a dog and a rabbit playing cards, circa 1956. (Photo by Evans/Three Lions)

A six-day-old hippopotamus is pictured next to his mother, Kara, aged 21, on September 12, 2012 at “Planet sauvage” (“Wild planet”) Zoo in Port-Saint-Pere, western France. The birth, a rare event for this species in captivity, occured on September 7, 2012 in the Zoo. (Photo by Frank Perry/AFP Photo)

The sun sets over the sea looking towards Lands End viewed from Gwenver beach near Sennen Cove on February 7, 2011 in Cornwall, England. (Photo by Matt Cardy/Getty Images)

A model presents a creation from Andres Sarda's Fall/Winter 2017 collection during the Mercedes-Benz Fashion Week in Madrid, Spain February 18, 2017. (Photo by Javier Barbancho/Reuters)

A police officer lies on the street after being run over by a bus during a protest against the increase in the price of public transport in San Cristobal, Venezuela March 29, 2016. (Photo by Carlos Eduardo Ramirez/Reuters)

Actress Charlize Theron attends the launch of DIOR VIII hosted by Charlize Theron at Dior Boutique on June 8, 2011 in New York City. (Photo by Jason Kempin/Getty Images)