Juno, a Beluga whale, greets a young viewer at the Mystic aquarium in Connecticut, USA on December 5, 2015. (Photo by Tim Clayton/Corbis)

A six-year-old acrobat performs on the opening of a tourist festival in Bozhou, Anhui province, China May 3, 2015. (Photo by Reuters/China Daily)

Nova Scotia Duck Tolling retriever Torrey competes in the 10th annual Petco Unleashed surfing dog contest at Imperial Beach, California August 1, 2015. Proceeds raised at the event go to benefit the San Diego Humane Society. (Photo by Mike Blake/Reuters)

A receptionist dinosaur robot performs at the new robot hotel, aptly called Henn na Hotel or Weird Hotel, in Sasebo, southwestern Japan, Wednesday, July 15, 2015. From the receptionist that does the check-in and check-out to the porter that’s a stand-on-wheels taking luggage up to the room, the hotel, that is run as part of Huis Ten Bosch amusement park, is “manned” almost totally by robots to save labor costs. (Photo by Shizuo Kambayashi/AP Photo)

As the sun sets on the Malecon in Havana on Friday January 23, 2015, Surenis Angulo de la Paz, 24, center, dances as group of locals play music around her. Behind her is Fidel Lopez, 55. (Photo by Sarah L. Voisin/The Washington Post)

Jimmy Arnold, an overweight boy from Rochester, bites into a cake. (Photo by Reg Birkett/Keystone/Getty Images). 14th April 1951

Libya's leader Muammar Gaddafi attends a meeting with Italian President Giorgio Napolitano at the Quirinale Palace on June 10, 2009 in Rome, Italy. Colonel Gaddafi is in Rome to attend a meeting of G8 Development Ministers. (Photo by Franco Origlia/Getty Images). ROME – JUNE 10

Three workers demonstrating the different types of gas masks used in mine rescue work. (Photo by Fox Photos/Getty Images). December 1925