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)

These stunning images show the 20-stone cat striking with lightning speed while the eight-foot reptile basks on a river island. The scene unfolded by the Cuiabá River in the Pantanal Wetlands of western Brazil. Photo: Jaguar attacks a Yacare Caiman. (Photo by Barcroft Media)

Renowned amphibian and reptile photographer Matthijs Kuijpers has released his first book, “Cold Instinct”. Kuijpers says the aim of the work is “for the viewer to abandon the fear and negative thoughts that often surround these animals”. What’s left is the bizarre beauty of these creatures in their simplest form – no backgrounds and no distractions. Here: Mossy frog (Theloderma corticale). (Photo by Matthijs Kuijpers/The Guardian)

Two keepers at the Australian Reptile Park in New South Wales struggle with Leonardo, an alligator snapping turtle weighing 45 kilos at the park in Gosford, NSW 2 July 2015. The 50cm long Leonardo – who was smuggled illegally into Australia and found in a Sydney sewer in November 2000 – was removed from his tank for an annual health check. And as a gesture to onlooking press photographers demonstrated his strength by snapping a piece of bamboo in half. (Photo by EPA/HO)

Zookeepers measure the length of a pueblan milk snake in the Reptile House of ZSL London Zoo as part of their annual weighing and measuring of their animals on August 25, 2011 in London, England. The heights and weights of over 750 different animal species at the zoo are recorded into the International Species Information System, to monitor their health and share the data with other zoos across the world. (Photo by Oli Scarff/Getty Images)

Perched on the snout of a crocodile, this brave frog will probably never realise just how much of a lucky escape it's had. For there's one reason the reptile's beady eye is fixed greedily on its visitor with jaws gaping wide in anticipation - it's feeding time. The crocodile had just devoured the first frog in his enclosure, but appeared unable to capture the second.

A park worker holds a monitor lizard at Lumpini park in Bangkok, Thailand, September 20, 2016. More than 400 of the Monitor lizards in the park will be caught by Thai authorities to relocate the reptile to a wildlife breeding center in the effort to control the creature population in the public park after the monitor lizard disturbing and causing several minor accident of people who jogging and cycling at the Lumpini Park. (Photo by Athit Perawongmetha/Reuters)

A Galapagos Tortoise shell is used as a foot rest at Heathrow Airport's Animal Reception Centre on January 25, 2011 in London, England. Many animals pass through the centre's doors ranging from exotic animals such as snow leopards and elephants, snakes and crocodiles, to the more common such as cats and dogs. In 2010 alone the centre processed approximately 10,500 cats and dogs, 1,300 birds, 105,000 day old chicks, 246,000 reptiles, 230 horses and 29 million fish. Most animals are part of zoo transfer schemes, the pet trade, or are pets in transit. (Photo by Dan Kitwood/Getty Images)