A boy poses with a butterfly on his face during a photocall to promote the “Sensational Butterflies” exhibition at the Natural History Museum in central London, on March 25, 2013. With around 400 live tropical butterflies and moths living in the temporary facility, visitors will get the chance to see them flying freely as well as looking for emerging butterflies at the hatchery window. Running from March 29 to September 15, 2013, the exhibition is housed in a structure in the museum grounds. (Photo by Leon Neal/AFP Photo)

Young acutus crocodile are pictured at Panagator, a sustainable crocodile farm, on the outskirts of Panama City September 11, 2015. Gladys Vallarino, owner of the farm and of a specialty boutique shop selling items made from crocodiles, says the farm looks after more than 19,000 Acutus and Fuscus species of crocodiles and donates five percent of its crocodiles annually to the Panamanian authorities to be put into the wild, in accordance with the regulations of the CITES (Convention of International Trade in Endangered Species). The handmade fashion items sell for $200 to $3,000. (Photo by Carlos Jasso/Reuters)

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 West African Slender-snouted Crocodile is pictured in its enclosure at the zoo of Abidjan, Ivory Coast September 9, 2016. (Photo by Luc Gnago/Reuters)

This is the amazing moment a heroic hippo saved a gnu from certain death. After being bitten by a crocodile, the large antelope is seen being dragged slowly under the water. But in a miraculous turn of events, a nearby hippo is seen making its way across the water to help the animal in its hour of need. Photo: One of the biggest hippos protects the gnu as it makes its way back to the shoreline, guarding it from any further attacks. (Photo by Vadim Onishchenko/Caters News)

Meet the snake-mimicking butterfly (Dynastor darius). While this slick master of disguise may show off impeccable imitation skills, prior to taking on this serpentine appearance it was simply a furry, nondescript caterpillar, and it looked pretty much how you would expect any old caterpillar to look.

A 5.5 metre massive crocodile makes mince meat out of a bull shark in Kakadu's Adelaide River on August 5, 2014 in Kakadu, Australia. The crocodile forced the bull shark into the mangroves and devoured the bull shark. A 43 year old Sydney father took these exclusive photos in the Northern Territory. (Photo by Andrew Paice/Getty Images)