The Brocken specters, an optical phenomenon that occurs when the sun shines from behind a climber or skier and their shadow falls on to mist or cloud.
This causes the shadow to magnify, re-reflecting off the cloud in question and cast back out again behind them a Big Grey Man.
The resulting ghostly shape can be accompanied by a rainbow halo effect called a glory – helping explain why this rare atmospheric occurrence often results in reports of frightening (BIG GREY MAN) and paranormal experiences among climbers.
There's long talk of a Big Grey Man in the Cairngorm mountains. Known locally for decades it enters popular folklore.
When Professor Normal Collie reported his experiences of Fearlas Mor (the Big Grey Man known locally) while on a trip to New Zealand in 1889.
Ever hiked in an ancient landscape?
Ever felt a strange presence? If you’re not sure, then ask someone who?! This short off-road route explores the myth of the Big Grey Man of Ben Macdhui.
Next time you're up in the Cairngorms and feel a chill wind blowing through the heather, spare a thought for the Big Grey Man.
Who knows what other creatures still lurk in the remote mountains of Scotland?
The Big Grey Man, said to over 6-feet tall, with long grey hair, dark eyes and an athletic build. His skin is pale, his hands are heavily-calloused from years' worth of manual labour.
He prefers to wear old clothes that are stained with oil and other fluids from hard work, rather than dress like someone from the élite class.
For centuries, people have haunted by a spectral presence on the windswept summit of Ben Macdhui. It's a place of mystery and fear where mind and matter blur.
The terror - something inherent in the place itself, steeped in the history of its wild landscape.
Wilderness is a dangerous place, with animals and natural elements that can provide a sense of danger. Some places are far more sinister than others.
The humbling vastness of the mountains, for instance, can seem like a prime hiding spot for a creature lurking below the surface.
Those who know these mountains well would report feeling an unseen presence or hearing strange noises in the dark crevices during their climb to victory.