Revellers take part in a zombie parade to celebrate Halloween in Kiev, Ukraine, October 31, 2015. (Photo by Valentyn Ogirenko/Reuters)

A blurred panaroma of Roemerberg historic center is reflected in a soap bubble in Frankfurt am Main, Germany, 09 July 2015. (Photo by Frank Rumpenhorst/EPA)

A fisherman throws his net to catch fish in a lagoon in Batticaloa November 24, 2015. (Photo by Dinuka Liyanawatte/Reuters)

Runners dressed in Christmas-themed outfits compete during a charity Santa run in Shanghai, China, November 29, 2015. (Photo by Aly Song/Reuters)

Lightning strikes near Jacobsdorf at the Oder-Spree district in eastern Germany, September 1, 2015. (Photo by Patrick Pleul/AFP Photo)

Tourists walk above a tea plantation in Enshi, Hubei province, December 27, 2015. (Photo by Reuters/Stringer)

A murmuration of migrating starlings is seen across the sky in southern Israel December 31, 2015. (Photo by Amir Cohen/Reuters)

A child parades on a float during the Bun Festival on May 25, 2015 in Hong Kong, Hong Kong. One of Hong Kong's most colourful cultural celebration event, Cheung Chau Bun Festival, will be staged on 25 May 2015 (Monday) till 26 May 2015 midnight (Tuesday). This festival has over 100 years of history. Every year, thousands of people descend upon the tiny island for The Piu Sik (Floating Colours) Parade, Lucky Bun (Ping On Bun) and The Bun Scrambling Competition, the ancient custom during the festival. (Photo by Lam Yik Fei/Getty Images)