Internally displaced Syrian children stand at the entrance of their makeshift shelter that is an underground cave in Om al-Seer, southern Idlib countryside, Syria December 26, 2015. (Photo by Khalil Ashawi/Reuters)

A woman takes part in a traditional horse parade through the streets of San Jose, Costa Rica December 26, 2015. Thousands of riders participated in the parade, which is part of annual year-end festivities. (Photo by Juan Carlos Ulate/Reuters)

People dressed as a zombie taking part in Zombie Parade on a streets of Belgrade during a zombie walk in Belgrade, on October 26, 2014. The zombie walk is part of the events of upcoming Serbian film fiction festival. (Photo by Oksana Toskic/SIPA Press)

A miniature sculpture in the shape of a home, created by self-taught artist Jadranko Djordjevic on a graphite pencil, is seen in Tuzla, Bosnia and Herzegovina April 26, 2016. (Photo by Dado Ruvic/Reuters)

A country music fan cools off in the wind on the second day of the Stagecoach country music festival in Indio, California April 26, 2014. (Photo by Mike Blake/Reuters)

Gothic enthusiast poses during the annual Wave-Gotik-Treffen music festival on May 26, 2012 in Leipzig, Germany. The event began in the 1990s and has since grown into one of the biggest gatherings of Goth scene followers in Europe with around 20,000 participants. (Photo by Adam Berry)

A hippopotamus is sprayed with water on a hot summer day at Anna National Zoological Park in Chennai, India on April 26, 2017. (Photo by Arun Sankar/AFP Photo)

Iraqi paramilitary troops fire towards Islamic State militants during a battle with Islamic State militants on the outskirts of the ancient city of Hatra near Mosul,Iraq April 26, 2017. (Photo by Reuters/Stringer)