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 boy looks back while he and another boy play on a Syrian military tank, destroyed during fighting with the Rebels, in the Syrian town of Azaz, on the outskirts of Aleppo, Sunday, September 2, 2012. (Photo by Muhammed Muheisen/AP Photo)

In this October 14, 2013 photo, ecology professor Ricardo Freitas catches a broad-snouted caiman to examine, then release back into the water channel in the affluent Recreio dos Bandeirantes suburb of Rio de Janeiro, Brazil. Caimans are like tanks, a very old species with a remarkable capacity for renovation that allows them to survive under extreme conditions where others couldn't, said Freitas, who runs the Instituto Jacare, or the Caiman Institute, which aims to protect the reptiles. (Photo by Felipe Dana/AP Photo)

The moon is seen in its waxing gibbous stage as it rises behind the helicopter from the original Batman television show, which people can ride at the New Jersey State Fair, Saturday, June 22, 2013, in East Rutherford, N.J. The moon, which will reach its full stage on Sunday, is expected to be 13.5 percent closer to earth during a phenomenon known as supermoon. (Photo by Julio Cortez/AP Photo)

Tank crew standing in front of M-4 tank, Ft. Knox, Kentucky, June, 1942. (Alfred Palmer/OWI/LOC)

Team McLaren Mercedes drivers Lewis Hamilton (L) and Jenson Button unveil the new MP-27 Formula 1 car at the McLaren technology centre on February 1, 2012 in Woking, England. (Photo by Mark Thompson/Getty Images)

Police officers clear the area near Borough market at London Bridge on June 3, 2017 in London, England. Police have responded to reports of a van hitting pedestrians on London Bridge in central London. (Photo by Dan Kitwood/Getty Images)

A man cuts dog meat at a dog meat restaurant ahead of local dog meat festival in Yulin, Guangxi Zhuang Autonomous Region, China on June 21, 2018. The festival in the southwestern town of Yulin has long drawn international criticism, with thousands of dogs traditionally being killed during the event. (Photo by Tyrone Siu/Reuters)