Bjorn, aged 5, smiles as he poses with a Owl butterfly during an event to launch the Sensational Butterflies exhibition at the Natural History Museum in London, Britain March 23, 2016. The exhibition opens to the public on March 24 and runs until September 11. (Photo by Dylan Martinez/Reuters)

Visitors dressed in superhero costumes attend the Paris Comics Expo at the Parc Floral in Paris, France, April 15, 2016. (Photo by Charles Platiau/Reuters)

A Ukrainian woman begs Ukrainian President Petro Poroshenko to stop the bombing in Donetsk after shell hit the residential area where she lives, killing two civilians in Donetsk's Kyibishevsky district, on January 29, 2015. (Photo by Manu Brabo/AFP Photo)

Contestants of a tattoo competition pose for photographs at the China TATTOO convention in Nanning, Guangxi Zhuang Autonomous Region, China, October 24, 2015. The annual convention was held in Nanning from October 23 to 25 this year. (Photo by Reuters/Stringer)

People slide down a 1,082 feet (330 metre) long inflatable water slide in Hong Kong, China August 22, 2015. (Photo by Tyrone Siu/Reuters)

Russia's synchronised swimming duet Aleksandr Maltsev (L) and Darina Valitova compete in the Mixed Duet Technical preliminary during the synchronised swimming competition at the 2015 FINA World Championships in Kazan on July 25, 2015. (Photo by Christophe Simon/AFP Photo)

Children guarded by Hungarian police play on the ground after being detained along with other migrants who illegally crossed from Serbia to Hungary near the village of Asotthalom, Hungary, September 16, 2015. (Photo by Dado Ruvic/Reuters)

A reveler wearing sheepfur costume is seen in front of a bonfire on which they burn a coffin symbolizing winter during the closing ceremony of the traditional carnival parade in Mohacs, 189 kms south of Budapest, Hungary, 07 February 2016. The carnival parade of people, the so-called busos, dressed in such costumes and frightening wooden masks, using various noisy wooden rattlers is traditionally held on the seventh weekend before Easter to drive away winter, and is a revival of a legend, which says that ethnic Croats ambushed the Osmanli Turkish troops, who escaped in panic seeing the terrifying figures during the Turkish occupation of Hungary. (Photo by Tamas Soki/EPA)