A hippopotamus performs during a show at the circus in Krasnoyarsk, Siberia, Russia, July 7, 2016. (Photo by Ilya Naymushin/Reuters)

Filipino children play as they are doing caroling activities on the street near an airport, days before Christmas in Manila, Philippines, 20 December 2017. Filipinos celebrate the longest Christmas in the world which starts as early as September every year. (Photo by Francis R. Malasig/EPA/EFE)

A boy plays with pelicans in Yoff, commune of Dakar, Senegal March 14, 2018. (Photo by Zohra Bensemra/Reuters)

A refugee sits in front of a Greek riot police cordon during a protest at the Greek-Macedonian border, near the Greek village of Idomeni, March 1, 2016. (Photo by Alexandros Avramidis/Reuters)

At a beauty contest to select the nation's Queen of Height during the first national convention of Tall People's Clubs in New York on July 29, 1949, little Charlie Young, only three feet, eleven inches tall, acting as judge, had a tough time making up his mind for the choice. The national minimum height requirement for women members is 5 feet 10 inches, and for men, 6 feet. (Photo by Robert Kradin/AP Photo)

A boy dressed as Lord Krishna is pictured while Hindu devotees march on the streets to celebrate Janmashtami festival, which marks the birth anniversary of Lord Krishna, in Dhaka, August 14, 2017. (Photo by Mohammad Ponir Hossain/Reuters)

With six-inch fangs and weighing in at 600lb, Saber and Janda are no ­ordinary house cats. Yet these huge Bengal tigers live in Janice Haley’s suburban garden and are treated like ordinary pets. They are fed by hand, get strokes and cuddles, and white male Saber goes to sleep sucking on her finger. Janice’s life changed 20 years ago when she spotted an advert for a tiger training course in her local paper – and two years later arrived home with her first cub. Then in 2002 she bought Janda, who is now 12. Photo: The pair are best of friends. (Photo by Ruaridh Connellan/Barcroft Media)

A young YPJ recruit (in pink) arrives to the training base for her first day in training near Derek City, Syria. The YPJ schedule is demanding and requires discipline – new soldiers in training get about 6 hours of sleep a night and wake up at 4 AM to begin exercising; afterwards, their day consists of a full schedule of drills and classroom lessons. Before joining the YPJ many of the girls had never participated in physical activity or sports before. (Photo by Erin Trieb/NBC News)