A hippopotamus performs during a show at the circus in Krasnoyarsk, Siberia, Russia, July 7, 2016. (Photo by Ilya Naymushin/Reuters)

Sebastien Laurent, manager of the Zoo, gives a slice of cake to Major, the holdest captive Orang-Outang in the world, as part of its 50th birthday ceremony, on July 17, 2012, at the La Boissiere-du-Doree Zoo near Nantes, western France. (Photo by Alain Jocard/AFP Photo)

Gentoo penguins begin the breeding season at Edinburgh Zoo on March 1, 2011 in Edinburgh, Scotland. The zoo keepers have just installed the nest rings in the penguin enclosure. The male penguins will then collect pebbles and offer them to the females to fill nest rings with, this helps keep the eggs and chick up off the ground and is part of their courtship display. (Photo by Jeff J Mitchell/Getty Images)ю EDINBURGH, SCOTLAND – MARCH 01

Four-year-old Chinese girl Jiaxue, who suffers from hairy black moles, sits on a bed at home November 4, 2006 in Changchun of Jilin Province, China. Jiaxue was born with black moles covering part of her back, breast, neck and face. Experts said the condition may be an atavism. (Photo by China Photos/Getty Images)

People pray inside a temple at the Janmashtami Hindu Festival at Bhaktivedanta Manor on August 22, 2011 in Watford, England. Up to 72,000 were expected to take part in the two day festival celebrating the birth of Krishna, in what is believed to be the largest Hindu festival gathering outside of India. (Photo by Dan Kitwood/Getty Images)

A workman jokes besides a work entitled “Monkey Detonator” by Banksy at Bonhams Auction house on September 16, 2011 in London, England. The piece makes up part of the “Urban Art” sale, and is expected to fetch between £70,000 - £90,000 GBP when it goes under the hammer on September 21, 2001 at Bonhams Auction house in London. (Photo by Dan Kitwood/Getty Images)

A Wiesel combat vehicle of the German Bundeswehr armed forces takes part in a demonstration for visitors prior to military exercises on September 28, 2011 near Munster, Germany. The Bundeswehr has instituted far-reaching changes in recent years, including an end to compulsory military service. (Photo by Sean Gallup/Getty Images)