A winter swimmer, wearing a Santa Claus hat to celebrate the upcoming Christmas, reacts as he plays on a frozen lake at a park in Shenyang, Liaoning province, December 22, 2014. The characters on the hat read: “Shenyang Winter Swimming”. (Photo by Reuters/Stringer)

Female sea lion “Sarasa” holds a hose with her mouse to help a trainer clean her room at the Shinagawa Aqua Stadium aquarium in Tokyo on December 30, 2014. The aquarium is carrying out year-end general cleaning of their facilities. (Photo by Yoshikazu Tsuno/AFP Photo)

Students hold their weapons before the swearing in ceremony for the military students, in Bucharest, Romania, Wednesday, October 25, 2017. The Romanian Army is proudly celebrating their Army Day and marking 100-years since the landmark battle of Marasesti, a key World War I battle in 1917 when Romanian and Russian soldiers defeated German troops, halting a German offensive. (Photo by Vadim Ghirda/AP Photo)

A woman jumps as a friend (not seen) takes a photo in front of a large drawing of Pope Francis depicting him as a superhero near the Vatican January 29, 2014. The Argentinian Pope is shown taking off into air with his right fist clenched in a classic Superman style. (Photo by Alessandro Bianchi/Reuters)

A picture made available on 07 March 2016 shows visitors petting and holding a Fennec fox, native to the Sahara, in the petting room at the Little Zoo Cafe, a business built to capitalize on Thais' love for exotic animals, and food, on the outskirts of Bangkok, Thailand, 05 March 2016. The cafe boasts Fennec foxes, Meerkat, native to parts of Africa, Silver Fox, Raccoon and Chinchillas, along with a menu of Thai food and Cheesecake, among other sweet deserts. Nature is a faraway fantasy in the bustling exhaust-filled cement city of Bangkok, fuelling a demand to own and be close to exotic pets. The trend to be near to a species that was once wild, in a city environment, far from the natural setting, has drawn criticism but continues to grow. (Photo by Barbara Walton/EPA)

An owner poses with her Maine Coon cat in front of a mirror during a cat exhibition in Bishkek on April 19, 2015. Cat lovers from Kyrgyzstan, Kazakhstan and Uzbekistan took part in the exhibition. (Photo by Vyacheslav Oseledko/AFP Photo)

Sunrise over Haleakala Crater, Haleakala National Park, Maui, Hawaii on April 26th, 2011. (Photo by Robert Bush/Alamy Stock Photo)

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)