Cheng Chen (R), a 27-year-old worker at a state-owned enterprise, poses for a photograph with his nephew who is wearing his home-made Iron Man armour, in Xuzhou, Jiangsu province April 13, 2015. It cost Cheng about 500 yuan ($81 USD) to make the armour, which weighs about 4 kilograms, with plastic boards and LED lights, local media reported. (Photo by Reuters/Stringer)

Performers dressed as Pikachu, a character from Pokemon series game titles, march during the Pikachu Outbreak event hosted by The Pokemon Co. on August 10, 2018 in Yokohama, Kanagawa, Japan. A total of 1, 500 Pikachus appear at the city's landmarks in the Minato Mirai area aiming to attract visitors and tourists to the city. The event will be held through until August 16. (Photo by Tomohiro Ohsumi/Getty Images)

Performers dressed as Pikachu, a character from Pokemon series game titles, march during the Pikachu Outbreak event hosted by The Pokemon Co. on August 9, 2017 in Yokohama, Kanagawa, Japan. A total of 1, 500 Pikachus appear at the city's landmarks in the Minato Mirai area aiming to attract visitors and tourists to the city. The event will be held through until August 15. (Photo by Tomohiro Ohsumi/Getty Images)

Afghan children wait as their mothers receive treatment at a USAID-funded health center on September 7, 2011 in Farza, Afghanistan. Almost 10 years after the 9/11 attacks and the U.S. invasion of Afghanistan, the U.S. government funds some of 500 Afghan health facilities nationwide, most run by non-governmental organizations contracted by the Afghan Ministry of Public Health. (Photo by John Moore/Getty Images)

Wanwisa, a Lao Yi Lai Heng Chinese opera performer waits backstage at the Plub Plachai temple on January 25, 2012 in Bangkok, Thailand. The traditional Chinese art form involving music, singing, martial arts and acting has a history of more than 500 years. There are about 30 members working with the group doing specials shows all week to celebrate the Chinese New year. The Chinese opera is popular in many parts of China, Malaysia, Singapore, Thailand and Macau. (Photo by Paula Bronstein/Getty Images)

A firefighter recovers after climbing the 1800 steps of the Costanera Centre Tower as part of the “Race for Life” aimed at encouraging organ donation in Chile, in Santiago, on October 16, 2016. More than 500 volunteer firefighters are expected to climb the 1800 steps of the tallest building in South America to promote and encourage organ donation in the country. (Photo by Claudio Reyes/AFP Photo)

A paddler races in a giant pumpkin during the annual regatta on Lake Pisiquid in Windsor, Nova Scotia, Sunday, October 11, 2015. Participants hollow out the massive gourds and pilot them across the 500 meter course. (Photo by Andrew Vaughan/The Canadian Press via AP Photo)

A Chinese tourist wears protective gloves as she holds a baby Siberian tiger as they pose for pictures at the Heilongjiang Siberian Tiger Park on August 16, 2017 in Harbin, northern China. The center is one of two Siberian tiger parks in the Chinese province of Heilongjiang, about 500 kilometers (300 miles) from the border with Russia. It is considered the world's largest for breeding the Siberian, or Amur, tiger which is listed as endangered by the World Wildlife Federation. (Photo by Kevin Frayer/Getty Images)