A donkey savors warming temperatures after a long winter at the zoo in Warsaw, Poland, on Wednesday, April 8, 2015. (Photo by Czarek Sokolowski/AP Photo)

A protester is taken away by policewomen after storming into the government headquarters in Hong Kong September 27, 2014. (Photo by Bobby Yip/Reuters)

A migrant boy sits on railway tracks at a train station in Tovarnik, Croatia, September 20, 2015. (Photo by Antonio Bronic/Reuters)

Indian Air Force soldiers toss their rifles as they perform during the full-dress rehearsal for Indian Air Force Day at the Hindon air force station on the outskirts of New Delhi October 6, 2015. (Photo by Anindito Mukherjee/Reuters)

Ruby Rose releases fire at the start of the start of the MTV European Music Awards in Milan, Italy, Sunday, October 25, 2015. (Photo by Luca Bruno/AP Photo)

A man dressed as a Santa Claus poses at the front of the Kollhoff Tower at Potsdamer Platz square in Berlin December 14, 2014. (Photo by Hannibal Hanschke/Reuters)

NFL player Rob Gronkowski, of the New England Patriots, from second left, accepts the best comeback athlete award with his brothers, NFL free agent Chris Gronkowski and former NFL player Dan Gronkowski at the ESPY Awards at the Microsoft Theater on Wednesday, July 15, 2015, in Los Angeles. (Photo by Chris Pizzello/Invision/AP Photo)