People perform during this year's flashmob of silly walks, based on the sketch from the television show Monty Python's Flying Circus by Monty Python troup, in Budapest, Hungary, 01 April 2019. (Photo by Zoltán Balogh/EPA/EFE)

People take photos with the skyline of the central business district in Singapore on September 10, 2015. (Photo by Edgar Su/Reuters)

Laborers work on scaffolding near a full-scale replica of the Sphinx at an unfinished movie and animation tourism theme park, in Chuzhou, Anhui province, March 27, 2015. (Photo by Reuters/China Daily)

Cosplayers are dressed as the Disney princesses outside Comic-Con on July 20, 2018 at the San Diego Convention Center in San Diego, California. More than 100,000 are expected at the annual comic and entertainment convention. (Photo by Mario Tama/Getty Images)

A tufted puffin is seen in Kamchatka Territory, Russia on July 17, 2018. (Photo by Yuri Smityuk/TASS)

A hummingbird is photographed during the National Orchid Exhibition at the Jose Celestino Mutis Botanical Garden in Bogota, Colombia Septermber 20, 2018. Picture taken September 20, 2018. (Photo by Luisa Gonzalez/Reuters)

Two students in Birmingham, United Kingdom dressed as policewomen enjoy a takeaway on October 31, 2018. Halloween party-goers enjoyed one hell of a night for the annual fright-fest. (Photo by Caters News Agency)

Split-view of a killer whale at sunrise off the coast of Northern Norway. At least half of the world’s killer whale populations are doomed to extinction due to pollution of the oceans, a new study says. (Photo by Audun Rikardsen/Science)