“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 woman sports a rainbow painted hand at the annual PrideFest celebration at Civic Center Park in Denver, Colorado June 18, 2016. (Photo by Andy Cross/The Denver Post)

Andrea Rossato, Italy. Professional; Candid. Children enjoy the simple pleasures of a seaside holiday. (Photo by Andrea Rossato/Sony World Photography Awards)

President Calvin Coolidge rides in a car during his inaugural parade in Washington, D.C., U.S. in March 1925. (Photo by Reuters/Library of Congress)

Corey Jurgensen runs along East Henry Avenue wearing an inflatable unicorn costume. Jurgensen has been wearing the costume during runs several times a week to cheer up others during this time of isolation but finds it therapeutic for herself as well to run through her Seminole Heights neighborhood wearing a silly costume, Thursday, April 16, 2020 in Tampa, Fla. (Photo by Martha Asencio Rhine/Tampa Bay Times via AP Photo)

A girl shows a fish she has caught in a bare- hand fish catching contest held in Housangyuan Village of Lyutan Township Wuyi County, east China' s Zhejiang Province, September 23, 2018. People across China hold various activities to celebrate the country' s first Farmers' Harvest Festival, which falls on Sept. 23 this year. (Photo by Zhang Jiancheng/Xinhua News Agency/Barcroft Images)

A young Sandinista guerrilla takes aim with his 45 pistol as he stands waiting to do combat with the Nicaraguan National Guard in Managua June 23, 1979. The guerrillas still occupy major parts of the Capitol City. (Photo by McLendon/AP Photo)

East Berliners crossing into the West Berlin on November 11, 1989 at the Potsdamer Platz, Germany. (Photo by Kai Wiedenhoefer)