A protester dressed as a clown holds an umbrella over a Swiss police officer on a motorbike during a May Day demonstration in Zurich, Switzerland on May 1, 2017. (Photo by Arnd Wiegmann/Reuters)

Men slide in the mud during the Boryeong Mud Festival at Daecheon Beach in Boryeong, South Korea, Saturday, July 22, 2017. The 20th annual mud festival features mud wrestling and mud sliding. (Photo by Ahn Young-joon/AP Photo)

Iranian Shiite Muslim women gather around a bonfire after rubbing mud on their body during the “Kharrah Mali” (Mud Rubbing) ritual to mark the Ashura religious ceremony in the city of Khorramabad, some 470 kms southwest of Tehran, early in the morning on October 1, 2017. “Khrreh Mali” or “Mud Rubbing” is a ritual that is held in the city of Khorramabad every year to commemorate the seventh century slaying of Prophet Mohammed' s grandson Imam Hussein, in which Iranian men roll over in mud and dry themselves by gathering around the bonfires before flagellating themselves. (Photo by Atta Kenare/AFP Photo)

American actress and singer Bella Thorne attends the GQ Mexico Men of The Year Awards 2017 on October 26, 2017 in Mexico City, Mexico. (Photo by Victor Chavez/Getty Images)

Heidi Klum, dressed as a werewolf, performs a dance from Michael Jackson's "Thriller" video her 18th Annual Halloween Party at Moxy Times Square on Tuesday, October 31, 2017, in New York. (Photo by Evan Agostini/Invision/AP Photo)

In this photo provided by Tasnim News Agency, relatives weep over the body of an earthquake victim, in Sarpol-e-Zahab, western Iran, Monday, November 13, 2017. An earthquake measuring 7.3 on the Richter scale rocked northern Iraq and Iran, the U.S. Geological Survey said on Sunday evening. Photo by Farzad Menati/Tasnim News Agency via AP Photo)

A wolf skin is on display for sale next to a painting of Russian communist revolutionary Vladimir Ilyich Ulyanov, also known as Lenin, at Izmailovo flea market in Moscow on December 3, 2017. (Photo by Mladen Antonov/AFP Photo)

A Kashmiri Shi'ite Muslim mourner flagellates himself during a Muharram procession to mark Ashura in Srinagar, India October 12, 2016. (Photo by Danish Ismail/Reuters)