An employee of the British Museum examines a silver coin dating from 900 AD which is part of the Silverdale Viking Hoard on December 14, 2011 in London, England. The hoard, which was discovered by local metal-detectorist Darren Webster in North Lancashire, comprises of 201 silver objects including arm-rings, coins, finger-rings, ingots, brooch fragments and fine wire braid. (Photo by Oli Scarff/Getty Images)

Demonstrators take part in a mass anti-Putin rally on December, 24, 2011 in Moscow, Russia. Tens of thousands of demonstrators rallied in cities across Russia to protest alleged vote fraud in recent parliamentary elections and to express their discontent with Prime Minister Vladimir Putin, leader of the dominant United Russia party. (Photo by Alexander Aleshkin/Epsilon/Getty Images)

Photo by: Rustem Adagamov; Source: LiveJournal

An elephant dressed in a Santa Claus costume gives out gifts to students to mark the Christmas season at a school in Ayutthaya province on December 24, 2010. The event was held as part of a campaign to promote Christmas in Thailand. (Photo by Pornchai Kittiwongsakul/AFP Photo)

Sea lion “Jay” paints a Chinese character reading “the Serpent” at the Hakkeijima Sea Paradise aquarium in Yokohama, suburban Tokyo on January 3, 2013. The event, marking the forthcoming Chinese lunar calender year of the snake was held as part of a New Year's attraction. (Photo by Kazuhiro Nogi/AFP Photo)

In this August 28, 1963 file photo, the top of the Washington Monument and part of a U.S. flag are reflected in the sunglasses of Austin Clinton Brown, 9, of Gainesville, Ga., as he poses at the Capitol where he joins others in the March on Washington. (Photo by AFP Photo)

Children residents take a selfie as they wait for the police to dance, an unconventional approach to connect the police with the community in rough neighbourhoods, as part of the “Tirando Barrio” (Marking territory) programme in Saltillo, Northern Mexico September 9, 2016. T-Shirt reads “Street Dancers”. (Photo by Daniel Becerril/Reuters)

A young Hindu priest crawls under a cow as part of worship rituals during Tihar festival in Kathmandu, Nepal, Sunday, October 30, 2016. Cows are considered sacred to Hindus and are worshipped during Tihar festival, one of the most important Hindu festivals dedicated to the Goddess of wealth Laxmi. (Photo by Niranjan Shrestha/AP Photo)

People take part in a Halloween street party at Lan Kwai Fong on October 31, 2016 in Hong Kong. Halloween, a contraction of All Hallows' Evening, falls on the day before All Saints' Day on November 1, a holiday when Christians remember their deceased loved ones. (Photo by Lam Yik Fei/Getty Images)