A mythical and ghostly creature has appeared in the wilds of the Scottish Highlands -- and has been caught on camera.

The rare white stag, from the red deer species, is believed to be among just a tiny handful living in Britain, according to a conservation group.

The John Muir Trust is now keeping the stag's location secret for fear of poachers.

"To see him amongst the other stags was truly thrilling because he does look like a ghost: you do a double-take," Trust Partnership Manager Fran Lockhart, who filmed the stag, told Reuters.

White stags are seen as a magical and powerful force in many mythologies.

The animal's ghostly glow comes from a recessive gene which causes leucism, a condition which reduces the normal brown colouring in hair and skin. They are not albinos, which have red eyes due to lack of pigment.

It is also said that for those who set eyes on the animal, a momentous moment is near.