“Hippo Chase”. As we approached the camp the Selinda Reserve of northern Botswana our boat passed by a hippo resting in the water. I turned around to look back at the boat's wake and saw the hippo charging after us! The hippo must've been tired from an all-nighter because he was angry. He rose way up out of the water three times trying to chase our boat! He was coming at us with such force that he created a wake of his own. Photo location: Selinda Reserve of northern Botswana. (Photo and caption by Curtis Simmons/National Geographic Photo Contest)

A fan dressed as “Loki” poses before the European premiere of “Avengers: Age of Ultron” at Westfield shopping centre in Shepherds Bush, London April 21, 2015. (Photo by Stefan Wermuth/Reuters)

Alex Plunkett, left, and Sean Hart, both of Arlington, Va., join hundreds participating in the annual International Pillow Fight Day on April 5. Massive pillow fights broke out on the Mall in Washington and in cities around the world. (Photo by Marvin Joseph/The Washington Post)

Football Soccer, England vs Wales, EURO 2016, Group B, Stade Bollaert-Delelis, Lens, France on June 16, 2016. Soccer fan Laura Woods from England fixes her makeup near riot police near the Lens stadium before the England vs Wales game. (Photo by Wolfgang Rattay/Reuters)

Workers look at exotic models and p*rn actresses standing on the top of a bus waving to people to promote the “Expo Sеx and Eroticism” adult exhibition in Mexico City, Mexico March 1, 2017. (Photo by Carlos Jasso/Reuters)

Michelle Wie of the USA lines up a putt on the second hole during the final round of the HSBC Women's Champions on the Tanjong Course at Sentosa Golf Club on March 5, 2017 in Singapore. (Photo by Scott Halleran/Getty Images)

Alice Cooke at the Sydney Women’s Reformatory in 1922. By the time she was 24 Alice Cooke had created an impressive number of aliases and at least two husbands, and was convicted of bigamy and theft. (Photo by My Colorful Past/Mediadrumworld)

Željava Air Base, situated on the border between Croatia and Bosnia and Herzegovina under Plješevica Mountain, near the city of Bihać, Bosnia, was the largest underground airport and military air base in the former Yugoslavia, and one of the largest in Europe. (Photo by Thomas Windisch/Exclusivepix Media)