Revelers march during the Greenwich Village Halloween Parade, Tuesday, October 31, 2017, in New York. (Photo by Andres Kudacki/AP Photo)

People wearing costumes walk during Halloween in Sierra Madre, California, U.S., October 31, 2017. (Photo by Mario Anzuoni/Reuters)

Security personnel patrol around West Lake in Hangzhou, Zhejiang Province, China, August 31, 2016. (Photo by Reuters/Stringer)

A vendor sells chili peppers at his stall at a market in Bangkok, Thailand March 31, 2016. (Photo by Jorge Silva/Reuters)

Revellers take part in a zombie parade to celebrate Halloween in Vina del Mar, October 31, 2015. (Photo by Rodrigo Garrido/Reuters)

A Tibetan woman with horses in a remote area of the Yushu Autonomous Prefecture of the Tibetan Plateau on May 31, 2016. (Photo by Giulia Marchi/The Washington Post)

Women in Kimono holding an umbrella walk on a street at Ginza shopping district in Tokyo, Japan, March 31, 2016. (Photo by Yuya Shino/Reuters)

A participant competes in the “Farinato Race” winter extreme run competition in Gijon, northern Spain, January 31, 2016. (Photo by Eloy Alonso/Reuters)