A hooded protester throws a petrol bomb to riot policemen during clashes, following a rally marking the 43rd anniversary of a 1973 student uprising against the military dictatorship that was ruling Greece, in Athens, Greece, November 17, 2016. (Photo by Yannis Behrakis/Reuters)

People out in Aberystwyth on “Booze Black Friday” or “Mad Friday” in Aberystwyth, Wales, UK on December 16, 2016. The “Booze Black Friday” is the last working Friday before Christmas when workers celebrate with their colleagues. Alcohol sales in pubs, clubs and off-licences rise dramatically on this day. (Photo by Keith Morris/Alamy Live News)

Tyson the Bulldog sits with reindeer antlers on Christmas Day at Central Park in Manhattan, New York City, U.S., December 25, 2016. (Photo by Andrew Kelly/Reuters)

In this July 5, 2016 photo, a tamed elephant rests in a pool of water by a road in Baduraliya, a village outside Colombo, Sri Lanka. Even as the country cracks down on illegal ownership, the enduring demand for elephants has the government planning to set up its own pool of captive animals to be hired out to temples for ceremonies and maintained with budget funds. (Photo by Eranga Jayawardena/AP Photo)

Sasha Muir and Margaret Davidson sit in a car as some of the 30 barbary macaques, known as the Middle Hill Troop after living between the top of Gibraltar rock and the town, show what happens when motorists forget to lock their luggage compartments, as Scotland’s only monkey drive-through section opens at Blair Drummond safari park in Stirling, Scotland on October 8, 2015. (Photo by Andrew Milligan/PA Wire)

A newborn grey seal pup is tended by its mother at Donna Nook, a nature reserve on the county’s coastline managed by Lincolnshire Wildlife Trust in Lincolnshire, UK on November 23, 2015. (Photo by David Tipling/Rex Shutterstock)

“Misty Morning”. Every morning, people expect sunny weather. Photo location: Bali, Indonesia. (Photo and caption by Henry Adam/National Geographic Photo Contest)

Ten segments of the Berlin Wall, which constitute the longest stretch outside of Berlin, are seen on display in Los Angeles, California September 18, 2014. On November 9, Germany will celebrate the 25th anniversary of the fall of the Berlin Wall. To mark the event Reuters Photographers around the world captured images of segments of the wall, which are kept as monuments in many countries from Taiwan to South Africa and Costa Rica. (Photo by Mario Anzuoni/Reuters)