A Tibetan rider fires his weapon as he perfoms his riding skills at the Qinghai Yushu Horse Racing Festival on July 27, 2007 in Yushu County of Yushu Tibetan Autonomous Prefecture, Qinghai Province, northwest China. The Horse Racing Festival of Tibetan nomads in Yushu Prefecture falls in late July and early August on the Tibetan calendar. During the festival, various equestrian skills will be performed along with singing, dancing and costume shows. (Photo by China Photos/Getty Images)

Super-cell thunderstorms, whirling tornados and lightning bolts illuminating the sky – these photos capture the terrifying brilliance of American storms. (Photo by Brandon Goforth/Solent News & Photo Agency)

Karis, an 8 week old lion cub, growls at a pumpkin as she explores a Halloween treat put in her enclosure by staff at Blair Drummond Safari Park near Stirling, Scotland, Tuesday, October 29, 2013. (Photo by Andrew Milligan/AP Photo/PA Wire)

Friends of Li Guojun drive a homemade tank-shaped vehicle in Kangping county, China. Li, a farmer who is a fan of tanks, spent six months with help from his friends to construct the almost 20-foot vehicle which weighs 2.5 tons. (Photo by Sheng Li/Reuters)

Two revelers dressed as toy soldiers gesture toward a police officer in a patrol car during the traditional carnival parade in Wuerzburg, Germany, 15 February 2015. Under the motto “Carnival Parade is cool” about 160 groups with over 3,000 members took part in one of the biggest carnival parades in southern Germany. (Photo by Daniel Karmann/EPA)

German shoemaker Georg Wessels (R) presents shoes to Win Zaw Oo, who according to his medical team, at 2.3 metres (7.5 ft), is Myanmar's tallest man, in Yangon March 26, 2014. (Photo by Reuters/Minzayar)

Two three-month-old female white Bengal tiger cubs play with a zoo keeper in their enclosure at the Buenos Aires' Zoo, in Argentina, on April 17, 2014. Captive white Bengal tiger Cloe, gave birth to three cubs – two females and one male – on January 14, 2014. (Photo by Juan Mabromata/AFP Photo)

“Zeybeks”. That's Dance, Sunward and Zeybeks. (Photo by Hasan Baglar/2014 Sony World Photography Awards)