A leg of a “diablito” frog (Oophaga sylvatica) is photographed in a laboratory at a laboratory in the zoo of Cali, Colombia, on July 19, 2019. Colombia is the second country with the largest number of amphibians in the world after Brazil. More than 40% of amphibian species worldwide are in danger of extinction. (Photo by Luis Robayo/AFP Photo)

A street vendor wearing a Santa Claus costume sits next to a girl at the boulevard of Sabana Grande in Caracas, Venezuela December 19, 2016. (Photo by Marco Bello/Reuters)

A Cavalier King Charles Spaniel competes in the Masters Agility Championship Finals competition during the 141st Westminster Kennel Club Dog Show in New York City, U.S. February 11, 2017. (Photo by Brendan McDermid/Reuters)

High-rise buildings are partly covered by heavy fog at Hong Kong's Victoria Harbour Monday, March 20, 2017. Fog blanketing Hong Kong is common in springtime and may greatly affect shipping and aviation. (Photo by Vincent Yu/AP Photo)

A dark Devon Rex cat is held by its owner during a competition in Bucharest, Romania, Saturday, September 26, 2015. More than 300 cats entered the international feline beauty competition in the Romanian capital. (Photo by Vadim Ghirda/AP Photo)

Skulls placed on the floor are seen during a ceremony held for the "Dia de las natitas" (Day of the Skull) celebrations at the General Cemetery of La Paz, November 8, 2015. Bolivians, who keep close relatives skulls at home as a macabre talisman, flock to the cemetery chapel once a year to have the craniums blessed and to bring themselves good luck in the future. (Photo by David Mercado/Reuters)

A young Afghan vendor waits for customers to buy sheep's heads at a roadside stall at the busy market in Kabul on November 29, 2015. (Photo by Wakil Kohsar/AFP Photo)

Brett Throckmorten of Barnes Bullets shows Logan Wingo how to sight down an electronic rifle in the trade booth area during the National Rifle Association's annual meeting in Nashville, Tennessee, April 11, 2015. (Photo by Harrison McClary/Reuters)