Katy Perry poses backstage during rehearsals for the 2017 MTV Video Music Awards at The Forum on August 25, 2017 in Inglewood, California. (Photo by John Shearer/Getty Images for MTV)

An aerial view shows a Russian Troika, a sledge drawn by three horses, competing on the ice-covered Yenisei River during the annual Ice Derby amateur horse race near the Siberian settlement of Novosyolovo, south of Krasnoyarsk, Russia March 17, 2018. (Photo by Ilya Naymushin/Reuters)

British sprinter Dina Asher-Smith arrives at The Fashion Awards 2018 In Partnership With Swarovski at Royal Albert Hall on December 10, 2018 in London, England. (Photo by Mike Marsland/BFC/Mike Marsland/Getty Images)

People on inflatable boats enjoy the weather on the Lake Lucerne in Sisikon, Switzerland, August 5, 2018. (Photo by Denis Balibouse/Reuters)

Syrian refugee girl Nur El-Huda, 9, shows a drawing of her home in Syria, in her classroom in Yayladagi refugee camp in Hatay province near the Turkish-Syrian border, Turkey, December 16, 2015. Syria's conflict has left hundreds of thousands dead, pushed millions more into exile, and had a profound effect on children who lost their homes or got caught up in the bloodletting. The drawings of young refugees living in Turkey show their memories of home and hopes for its future. The pictures also point to the mental scars borne by 2.3 million Syrian refugees living in Turkey, more than half of them children. (Photo by Umit Bektas/Reuters)

A group of frogs hitched a lift on a passing crocodile. Clearly comfortable in the croc’s company the amphibians wait patiently for their chauffeur to move. But the bemused crocodile doesn’t appear to be going anywhere in a hurry. The hilarious images were captured by Tanto Yensen, 36, from Jakarta, Indonesia. (Photo by Tanto Yensen/Media Drum World Photo Agency)

A newly born Sitatunga calf seen at ZSL Whipsnade Zoo on November 24, 2016 in Whipsnade, England. The swamp-dwelling species, also known as a marshbuck, is Africa's only true amphibious antelope. It was snuggled up in the leaves and almost perfectly camouflaged as it mother tended it. (Photo by Tony Margiocchi/Barcroft Images)

In this photograph taken on October 4, 2016, an Afghan baker prepares bread at his shop as he waits for customers in Lashkar Gah, the capital city of Helmand province. For years Helmand was the centerpiece of the Western military intervention in Afghanistan only for it to slip deeper into a quagmire of instability, with almost the entire southern province teetering on the verge of collapse. Intensified fighting has killed hundreds and forced thousands to flee to besieged capital Lashkar Gah, sparking a humanitarian crisis as the city – one of the last government- held enclaves – risks falling to the Taliban' s repeated ferocious assaults. (Photo by Wakil Kohsar/AFP Photo)