Cheetah cubs play fighting in Ndutu, Tanzania.
Photograph taken by Amy Johnson.

Cheetah cubs play fighting in Ndutu, Tanzania.

Photograph taken by Amy Johnson.

Photo by Roggies world of photography

Photo by Roggies world of photography

A hippopotamus stares at the photographer from its enclosure at the San Antonio Zoo in Texas.  Picture: BARCROFT MEDIA

A hippopotamus stares at the photographer from its enclosure at the San Antonio Zoo in Texas.  Picture: BARCROFT MEDIA

A sleeping lion cub in a pile of paws, in Serengeti National park, Tanzania.
Photograph by Amy Johnson.

A sleeping lion cub in a pile of paws, in Serengeti National park, Tanzania.

Photograph by Amy Johnson.

Gorilla baby, Allwetter Zoo Münster by nikaspad

Gorilla baby, Allwetter Zoo Münster by nikaspad

The Thinker. Photo by Simplicity of Life

The Thinker. Photo by Simplicity of Life

Photographer Xabi Barreneche, 23, watched as Farell the cat mischievously looks on at Leon the fish.  Picture: SOLENT

Photographer Xabi Barreneche, 23, watched as Farell the cat mischievously looks on at Leon the fish.  Picture: SOLENT

A sleeping lion cub in a pile of paws, in Serengeti National park, Tanzania.
Photograph by Amy Johnson.

A sleeping lion cub in a pile of paws, in Serengeti National park, Tanzania.

Photograph by Amy Johnson.

Adán (Mexican rosy boa juvenile) on Flickr, by teleos.

Adán (Mexican rosy boa juvenile) on Flickr, by teleos.

by: sleepykins
Reptile keeper Damian Goodall releases one of the three baby turtles into the exhibit tank at Melbourne Zoo. Reptile keepers have achieved a significant Australian first, the breeding of the critically endangered Chinese three-striped box turtle, generally known as golden coin turtles. These turtles are native to creeks in rainforests throughout South-east Asia and southern China.  Picture: David Caird/Newspix / Rex Features

Reptile keeper Damian Goodall releases one of the three baby turtles into the exhibit tank at Melbourne Zoo. Reptile keepers have achieved a significant Australian first, the breeding of the critically endangered Chinese three-striped box turtle, generally known as golden coin turtles. These turtles are native to creeks in rainforests throughout South-east Asia and southern China.  Picture: David Caird/Newspix / Rex Features

Submission by: low-iso

Submission by: low-iso

Elephant Seals along the central coast of California. | By: Blonde Photography (FB) / Tumblr

Elephant Seals along the central coast of California. | By: Blonde Photography (FB) / Tumblr

A male tiger, T24, drinking from a watering hole in Ranthambore National park.
Photograph by Amy Johnson.

A male tiger, T24, drinking from a watering hole in Ranthambore National park.

Photograph by Amy Johnson.

Wildlife photographer Donald Jones photographed these playful fox cubs outside their burrow in the western region of Montana, US  Picture: Donald M.Jones/Minden/Solent

Wildlife photographer Donald Jones photographed these playful fox cubs outside their burrow in the western region of Montana, US  Picture: Donald M.Jones/Minden/Solent