A tank's barrel is seen on the course of the Tank Biathlon competition during the International Army Games 2016 in Alabino, outside Moscow, Russia, July 30, 2016. (Photo by Maxim Zmeyev/Reuters)

Tank crew standing in front of M-4 tank, Ft. Knox, Kentucky, June, 1942. (Alfred Palmer/OWI/LOC)

Body modification and tattoo artist Andrea Aguilar, 26, known as leopard woman, at the Quito Tattoo Convention shows off her work during the last day of the event in Quito, Ecuador September 27, 2015. (Photo by Guillermo Granja/Reuters)

Baby clouded leopards, born early in March 2015, are presented by zoo keepers at the Olmense Zoo in Olmen, Belgium, April 16, 2015. The clouded leopard is an endangered species with only some 10,000 specimen remaining on earth, said Robby Van der Velden, a biologist at the Olmense Zoo. (Photo by Yves Herman/Reuters)

A chimpanzee feeding a leopard cub at Southam Park Zoo, Warwickshire. (Photo by Ian Tyas/Keystone Features/Getty Images). 1971

A wild leopard runs on the stairs as it tries to escape from a compound of a house in Kathmandu, Nepal June 1, 2016. (Photo by Navesh Chitrakar/Reuters)

A curious leopard cub toys with a camera at MalaMala Game Reserve in Mpumalanga Province, South Africa. (Photo by Barcroft Media)

A leopard leaps into a muddy waterhole to catch a fish on August 13, 2015, in the Savuti Channel in Botswana. A leopard leaps into a muddy waterhole to catch a fish in the Savuti Channel in Botswana. The spotted predator stood poised waiting for a fish to appear – before leaping in ferociously with lightening reflexes. Coated in a layer of thick dark mud the big cat emerged from the water clutching the fish in its jaws. The fishing leopards of Savuti are known for their unique skills in catching fish – but have rarely been photographed. (Photo by Greatstock/Barcroft Media)