A visitor holds up her toy bunny to the aquarium glass in front of Aurora the Russian polar bear at the Sao Paulo Aquarium in Sao Paulo, Brazil, Thursday, April 16, 2015. (Photo by Andre Penner/AP Photo)
South Vietnamese forces escort suspected Viet Cong officer Nguyen Van Lem (also known as Bay Lop) on a Saigon street February 1, 1968, early in the Tet Offensive. Moments later, Lem was executed by Gen. Nguyen Ngoc Loan, chief of the national police. (Photo by Eddie Adams/AP Photo)
A polar bear cub, born on November 26, 2014, and its mother Flocke spend time outdoors on March 9, 2015 at the Marineland animal exhibition park in the French Riviera city of Antibes. AFP PHOTO / VALERY HACHE (Photo credit should read VALERY HACHE/AFP/Getty Images)