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)

Swimmers in fancy costume take part in the New Year's Day swim at Saundersfoot in Wales, Britain, January 1, 2017. (Photo by Rebecca Naden/Reuters)

Drivers take part in a demolition derby organised by the Malta Motor Sports Association to raise funds for charity in Ta' Qali, outside Valletta, Malta, January 8, 2017. (Photo by Darrin Zammit Lupi/Reuters)

People dressed as Father Frost, the equivalent of Santa Claus, and Snow Maiden take part in the contest “Yolka-fest-2014” (Fir-festival-2014) in Minsk December 12, 2014. (Photo by Vasily Fedosenko/Reuters)

A reveller from Tom Maior Samba School takes part in a carnival at Anhembi Sambadrome in Sao Paulo February 14, 2015. (Photo by Nacho Doce/Reuters)

Girls suffering from dwarfism take part in the disability pride parade in New York, July 12, 2015. The parade grand marshal was former U.S. Sen. Tom Harkin, the Iowa Democrat who 25 years ago sponsored the Americans With Disabilities Act. (Photo by Eduardo Munoz/Reuters)

Air National Guard takes to the skies over Puget Sound during Seafair 2015 on Thurs., July 30, 2015 in Seattle, Wash. (Photo by Matt Mills McKnight/AP Images for John Klatt Airshows, Inc.)

A clown performs next to the Monument to the Revolution as he takes part in the Latin American Clown Convention in Mexico City, Mexico, October 21, 2015. The convention will be held from October 19 to 22 in Mexico City. (Photo by Henry Romero/Reuters)