A South Sudanese People Liberation Army (SPLA) soldier patrols the streets in Malakal on January 21, 2014. (Photo by Harrison Ngethi/AFP Photo)

Catherine, Duchess of Cambridge speaks to soldiers as she arrives at Calgary Airport on July 7, 2011 in Calgary, Canada. (Photo by Chris Jackson/Getty Images)

A German Shepard bares its teeth during Schutzhund attack dog training at Witmer-Tyson Imports February 14, 2002 in Newark, CA. (Photo by Justin Sullivan/Getty Images)

O Santa Claus of Australia competes in the mens 80–84 years 100 metres heats during day two of the 2009 Sydney World Masters Games at Sydney Olympic Park on October 11, 2009 in Sydney, Australia. (Photo by Mark Nolan/Getty Images)

An iguana in Bali helped Julij Kopilović, age eight, from Slovenia, earn second runner-up in Amazing Animals. (Photo by Julij Kopilović/National Geographic)

Clouds gather as walkers pause atop a ridge in Mountain View, California January 7, 2016. (Photo by Noah Berger/Reuters)

A ring-tailed lemur is pictured at Zoom Torino, a zoological park in Cumiana near Turin, on April 22, 2015. Zoom Torino is a new immersive zoological park, where animals can be seen without bars or cages, only natural barriers ensure the visit. (Photo by Marco Bertorello/AFP Photo)

Turkey's Merve Aydin cries after she came in last in her women's 800m round 1 heat at the London 2012 Olympic Games at the Olympic Stadium August 8, 2012. (Photo by Lucy Nicholson/Reuters)