Four-month-old fox cubs squaring up to each other in Walthamstow, England on August 7, 2015. (Photo by Greg Morgan/Barcroft Media)

Attendees at Wizard World Comic Con walk through hallways in Chicago, Illinois, United States, August 22, 2015. (Photo by Jim Young/Reuters)

Ukrainian Air Force officers attend a graduation ceremony at the National University of Defence of Ukraine in Kiev, April 24, 2015. (Photo by Gleb Garanich/Reuters)

A competitor participates in the Tough Mudder challenge near Henley-on-Thames in southern England May 2, 2015. (Photo by Eddie Keogh/Reuters)

A clothing shop displays its merchandise in the rebel-controlled city of Idlib, Syria November 7, 2015. (Photo by Ammar Abdullah/Reuters)

People are reflected in mirrors as they walk in a busy shopping district in Tokyo, Japan, December 25, 2015. (Photo by Thomas Peter/Reuters)

Models walk the runway at the Maria Escote show during Madrid Fashion Week Fall/Winter 2015/16 at Ifema on February 10, 2015 in Madrid, Spain. (Photo by Carlos Alvarez/Getty Images)

A model is filmed backstage before the Jeremy Scott Fall/Winter 2015 collection presentation at New York Fashion Week February 18, 2015. (Photo by Andrew Kelly/Reuters)