Contestants of a tattoo competition pose for photographs at the China TATTOO convention in Nanning, Guangxi Zhuang Autonomous Region, China, October 24, 2015. The annual convention was held in Nanning from October 23 to 25 this year. (Photo by Reuters/Stringer)

Mud-covered tourists pretend to be trapped inside a mud prison at the Daecheon Beach Mud Plaza in the city of Boryeong on South Korea's west coast, July 17, as they take part in the Boryeong Mud Festival, which opened that day and runs through July 26. Boryeong mud is rich in natural mineral component and is considered to prevent skin aging. (Photo by EPA/Yonhap)

Filipino boys play basketball at an improvised court hooked on multi-layered tombs at a public cemetery in Navotas, north of Manila, Philippines on Thursday Oct. 31, 2013. Filipinos are expected to flock to cemeteries on November 1 to remember their dead as they observe All Saints Day in this predominantly Roman Catholic country. (Photo by Aaron Favila/AP Photo)

38 year old Prabhat Sinha, from Assam, carries a load of coal weighing 60kg's, supported by a head-strap, as he ascends the staircase of a coal mine on April 16, 2011 near the village of Khliehriat, in the district of Jaintia Hills, India. (Photo by Daniel Berehulak/Getty Images)

These stunning pictures show a normally vicious tiger calmly swimming in a pool of algae, on Jule 9, 2014. The powerful cat takes a refreshing break by taking a dip in the bright green algae. But it looks like this big cat is scared of getting his head wet as he strains to keep it above the water. After splashing around for a bit the tiger gets out and tries to air-dry with specks of the vegetation dripping off his fur. The striking pictures were taken at Copenhagen zoo by snapper Soren Lundgren Neilson. (Photo by Soren Nielsen/Caters News)

A street cleaner demonstrates his martial arts skills in front of a closed shop near Beijing's Tiananmen Square September 2, 2015 as the capital prepares for tomorrow's parade. (Photo by Damir Sagolj/Reuters)

Aerobatic pilot Sean D. Tucker flies in the two-seat Oracle Extra airplane over downtown Chicago skyline, Wednesday, June 8, 2016. Tucker will perform before the start of of the America's Cup World Series racing on Saturday and Sunday. (Photo by Kiichiro Sato/AP Photo)