Four men dressed as zombies participate in a Zombie Walk procession in the streets of Paris October 12, 2013. (Photo by Benoit Tessier/Reuters)

Young people fight for fun with their pillows, during the International Pillow Fight Day at the Place des Grottes, in Geneva, Switzerland, Saturday, April 4, 2015. The annual International Pillow Fight Day takes place in hundreds of cities around the world. (Photo by Salvatore Di Nolfi/AP Photo/Keystone)

A pet owner holds his guinea pig named Riec as Father Francisco bestows a blessing on the pet rodent during a feast day Mass in honor of Saint Anthony, the patron saint of animals, at the Saint Fernando church, in Mexico City, Saturday, January 17, 2015. Many people in Mexico bring their pets to churches to be blessed by the priest on this day. (Photo by Marco Ugarte/AP Photo)

A Nepalese Hindu devotee takes a holy bath as they mark the Mother's Day Festival at Matathirtha on the outskirts of Kathmandu on May 6, 2016. Nepalese Hindu devotees come from across the country to bathe, offer prayers and leave offerings at the Matathirtha Temple during the event, which honours mothers who have passed away. (Photo by Prakash Mathema/AFP Photo)

Rebecca Smith poses for a photograph during winter solstice with her Irish Wolfhound dog called Amazing Grace at the 5000 year old stone age tomb of Newgrange (not in view) in the Boyne Valley at sunrise in Newgrange, Ireland, December 21, 2016. (Photo by Clodagh Kilcoyne/Reuters)

Soldiers march to mark the Armed Forces Day and commemorate the landing of the yacht Granma, which brought the Castro brothers, Ernesto “Che” Guevara and others from Mexico to Cuba to start the revolution in 1959, in Havana, Cuba, January 2, 2017. (Photo by Alexandre Meneghini/Reuters)

A man dressed as one of the Three Kings greets people during the Epiphany parade in Gijon, Spain January 5, 2017. (Photo by Eloy Alonso/Reuters)

Mary, 8-months-old female orphan elephant, drinks milk at Winga Baw Elephant Conservation Camp during the ceremony to mark World Elephant Day at Bago Region, Myanmar, 12 August 2017. Winga Baw Elephant Conservation Camp, 34-hectare former timber camp for logs located in Bago Region, currently has 14 elephants and was opened for recreation for locals as well as for tourists. World Elephant Day is marked annually on 12 August. (Photo by Lynn Bo Bo/EPA/EFE)