It’s not easy being green…
Well it is actually, particularly if you were born that way – as these unique puppies were.
The pair were part of a litter of five pups born to a breeder of hunting dogs in the Spanish town of Laguna de Duero.
Owner Aida Vallelado Molina said: “I couldn’t believe it when I saw them.
"I thought the puppies were maybe dirty somehow and I tried to clean them, but the colour wouldn't come off and then I realised it was the colour of their fur."
But unlike the Incredible Hulk, the animals were smaller and weaker than their siblings. One of them, a female, died shortly after birth but the male pup is still alive although weak.
He is also gradually beginning to lose his colouring.
Vet Daniel Valverde is probing the case, and said: "There are no other recorded cases of this happening in Spanish scientific literature. I am carrying out virological and bacteriological tests to try and find an answer."
The two Spanish puppies are however not the first reported examples of green pups. In 2012 a green Labrador puppy was born in England that lost its green hue after ten days.
The cause for the colouring at that time was given as exposure to a substance called biliverdin, which can be found in the placenta.