These powerful images capture the spear-wielding tribes of Papua new Guinea who believe they are possessed with the spirit of the crocodile. They show how the Kangunaman clansmen scar their backs to resemble reptile scales while the Huli Wigmen wear elaborate headdresses to signal they are ready for battle. (Photo by Trevor Cole/Media Drum World)

Tattoo artist Tokyo Hiro draws a scorpion to be tattooed on a customer at the Tattoo the Earth Festival August 9, 2002 in Oakland, California. The Tattoo the Earth festival focuses on the tattooing culture and is the largest tattoo event of its kind. (Photo by Justin Sullivan/Getty Images)

Turkana tribesmen walk with guns in order to protect their cattle from rival Pokot and Sambur tribesmen near Baragoy, Kenya February 14, 2017. Cattle rustling and competition for grazing have long troubled northern Kenya, but severe drought and political rivalries ahead of the elections have exacerbated the situation between ethnic tribes. (Photo by Goran Tomasevic/Reuters)

In this photo provided by Mickey Nuttall, members of an international team of skydivers join hands, flying head-down to build their world record skydiving formation, Friday, July 31, 2015, over Ottawa, Ill. (Photo by Jason Peters via AP Photo)

“This cheeky polar bear tried to hitch a lift off an unsuspecting driver by clambering into the back of his pick-up truck. The curious creature spent about half an hour inspecting the vehicle and its owner before casually trying to climb aboard. However, the truck must not have been up to scratch because the 7ft bear, weighing approximately 300lbs, promptly jumped back out and sauntered off”. – Barcroft Media. Photo: “Awright mate, any chance of a lift to the North Pole?” (Photo by Steven Kazlowski/Barcroft Media)

This year’s World Nomad Games, a celebration of nomadic heritage, took place in the Issyk-Kul province of Kyrgyzstan. Eleanor Moseman photographed female competitors who had travelled from all over central Asia and eastern Europe, and explored the difficulties and challenges they face as competitors. (Photo by Eleanor Moseman/The Guardian)