A man from Dinka tribe holds his AK-47 rifle in front of cows in a Dinka cattle herders camp near Rumbek, capital of the Lakes State in central South Sudan December 14, 2013. (Photo by Goran Tomasevic/Reuters)

A competitor reacts as she emerges from the water during the Tough Guy event in Perton, central England, January 26, 2014. The annual Tough Guy race – “the toughest race in the world” – at Perton in Staffordshire. Tough Guy claims to be the world’s most demanding one-day survival ordeal. First staged in 1987, the Tough Guy Challenge has been widely described as one of the hardest races of it’s type with up to one-third of the starters failing to finish in a typical year. (Photo by Darren Staples/Reuters)

People participate in a pillow fight to mark International Pillow Fight Day in the Heroes' Square, in central Budapest, Hungary, Saturday, April 2, 2016. The Pillow Fight Day attracts tens of thousands people in more than 100 cities all over the World each year. ((Photo by Zoltan Balogh/MTI via AP Photo)

North Korean military participate in the celebration of the 70th anniversary of the founding of the ruling Workers' Party of Korea, in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang on early October 11, 2015. (Photo by Reuters/KCNA)

Customers clink their cups as they sit in Crazy Toilet Cafe in central Moscow, Russia October 30, 2015. A new Moscow cafe, opened on Friday, serves food to its guests with crockery designed to look like small baths and urinals, in toilet-themed interior with seats resembling toilets, local media reported. (Photo by Sergei Karpukhin/Reuters)

Storm chasing photographer Mike Hollingshead makes a living following the worst storms in America, from snarling tornadoes chewing up the Kansas farmland to supercell thunderstorms massing over the Dakotas. His style is to get right in the path of the storm. While he says it’s less scary than you think – because most of the storm consists of heavy rain – it’s still extremely stressful. Photo: Vivid sunset under severe storm in central Nebraska August 17, 2005. (Photo by Mike Hollingshead)

A drone flies above World Surf League World Title winner Hawaian surfer John John Florence during the final heat of the Portuguese stage of the World Surf League championship at Supertubos beach near Peniche, central Portugal, on October 25, 2016. (Photo by Francisco Leong/AFP Photo)

Nepalese police officers worship a dog during the dog festival as part of Tihar celebrations, also called Diwali, at the Central Police Dog Training School in Kathmandu, Nepal October 29, 2016. Dogs are worshipped to acknowledge their role in providing security during Tihar festival, one of the most important Hindu festivals that is also dedicated to the worship of the goddess of wealth Laxmi. (Photo by Navesh Chitrakar/Reuters)