“Unexpected humour”. The Dog and the Faucet, in Kolkata, India on January 2017. (Photo by Pau Buscató/The Guardian)

A chimpanzee feeding a leopard cub at Southam Park Zoo, Warwickshire. (Photo by Ian Tyas/Keystone Features/Getty Images). 1971

“This grey adult male seal enjoys a good grin while lying on the beach”. (Photo by Michael Hutch/SplashdownDirect via Rex USA)

In this Wednesday, May 23, 2012 photograph, a young deer and a cat share a moment in Feench village near Jodhpur, Rajasthan state, India. (Photo by AP Photo)

“They're some of the most intriguing and complex creatures on the planet but they really do have nothing to hide – because theyre totally see-through. Transparent animals – creatures with clear glass-like skin – can be found all over the world but their very existence is still shrouded in mystery. The fascinating organisms verge on the invisible and their translucent skin often helps them elude predators”. – Caters News. Photo: Thornback Skate. (Photo by Ken Lucas/Caters News)

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)

A walruses at Hagenbeck Zoo in Hamburg, Germany on July, 7, 2015. (Photo by Werner Struss/Startraks action)