A man is silhouetted in front of the Allianz-Arena as he walks his dogs at sunrise in Munich, southern Germany, Friday, April 10, 2015. (Photo by Peter Kneffel/AP Photo/DPA)

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)

A participant takes part in a zombie parade during the Brussels International Fantastic Film Festival in Brussels, Belgium, April 9, 2016. (Photo by Yves Herman/Reuters)

Singer Halsey has her dress adjusted before she poses during the premiere of the film “The Huntsman: Winter's War” in Los Angeles, California, April 11, 2016. (Photo by Kevork Djansezian/Reuters)

Sumo wrestlers compete during the annual “Honozumo” ceremonial sumo tournament dedicated to the Yasukuni Shrine in Tokyo, Japan, April 18, 2016. (Photo by Yuya Shino/Reuters)

People walk past a man preaching along a train track in Ikeja district in Nigeria's commercial capital Lagos April 12, 2016. (Photo by Akintunde Akinleye/Reuters)

A model presents a creation by Kazakhstan's design house Khafiz Khan during Kazakhstan Fashion Week in Almaty, Kazakhstan, April 21, 2016. (Photo by Shamil Zhumatov/Reuters)

A woman takes a picture of a Maserati's SUV model Levante during the Auto China 2016 show in Beijing, China April 25, 2016. (Photo by Kim Kyung-Hoon/Reuters)