A woman holds a skull during a “Dia de los natitas” (Day of the Skull) ceremony at the Cementerio General of La Paz. (Photo by David Mercado/Reuters)

Cloud inversion taken at Sunrise in Mam Tor, Derbyshire, UK on August 30, 2016. (Photo by David Zdanowicz/Rex Features/Shutterstock)

A member of the Diablada Urus group attends the carnival parade in Oruro, Bolivia February 25, 2017. (Photo by David Mercado/Reuters)

People walk on the street in Samara, Russia on July 18, 2017. (Photo by David Mdzinarishvili/Reuters)

A storm trooper feeds a walker in the grass, taken in Glasgow, Scotland, December 2016. Tiny Storm Troopers and a mini Darth Vader are captured doing everyday activities – from taking a bath, to wrapping presents. Scottish Artist and Photographer, David Giliver created these scenes over a period of two years using toys and miniature props. (Photo by David Gilliver/Barcroft Images)

David Nickerson, 28, competes dressed as artist Bob Ross, during the ZJ Boarding House Halloween Surf Contest in Santa Monica, California October 26, 2013. (Photo by Lucy Nicholson/Reuters)

Female of pygmy hippopotamus called Malaya from Netherlands in zoo in Dvur Kralove nad Labem, Czech Republic, February 22, 2016. (Photo by David Tanecek/CTK via ZUMA Press)

A woman takes part in a four-minute flash mob pillow fight at the Old Town Square in Prague, Czech Republic, December 22, 2016. (Photo by David W. Cerny/Reuters)