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)

A Thai and foreign revelers battle with water guns during the annual Songkran celebration at Khaosan Road, a tourist spot in Bangkok, Thailand, 12 April 2017. The four southeast Asian nations of Myanmar, Thailand, Cambodia and Laos started the Buddhist new year, known as Thingyan in Myanmar and Songkran in Thailand, on April 13. (Photo by Rungroj Yongrit/EPA)

Revellers take part in a Zombie Walk in Asbury Park, New Jersey October 4, 2014. Thousands of revellers met in Asbury park to attempt to break the Guinness World Record of the largest zombie gathering in the world and raise awareness for brain cancer. (Photo by Eduardo Munoz/Reuters)

People ride a Ferris wheel as fireworks illuminate the sky over Edinburgh, Scotland. (Photo by David Cheskin/Press Association)

Indian brides and grooms wait for the start of a mass wedding in New Delhi on June 15, 2014. Some 92 low-income and disabled couples tied the knot in a free mass wedding ceremony organised by the non-profit organisation Narayan Sewa Sansthan. (Photo by Chandan Khanna/AFP Photo)

Camelot, with rider Kris Anderson, wins an exhibition race billed as “The Cameltonian” at the Meadowlands Race Track in East Rutherford, New Jersey June 21, 2014. Run by Hedrick's Promotions in Nickerson, Kansas, this is the third year the race has been run at the track, in tandem with an ostrich race. (Photo by Ray Stubblebine/Reuters)