Am Fear Liath Mór, or Big Grey Man or The Grey Man of Ben MacDhui is known to stalk the people who climb the mountain Ben Macdhui, the second highest peak in Scotland. Because of the high levels of fog there, not many people have seen it.
Some believe the Grey Man to be a guardian of the mountain, but others believe him to be the guardian of a gate to other dimensions.
The grey man is reported to be very tall humanoid, at least 8 feet high (Although sometimes as high as 30 feet). It is covered in short, gray hair, hence the name. Many times the witnesses didn't even see it, but still could hear it due to the loud footsteps. Many believe the Gray Man is a relative to sasquatch/bigfoot. It normally stalks its victims until they realize that it is following them, and then it chases them. This is a common pattern. It walks on two legs, and walks (and runs) like a normal person.
But more frequently, the Grey Man is encountered in physical sensation, but without a true physical form. Sensations of this type include vast, dark blurs which obscure the sky, strange crunching noises, echoing footsteps which pursue the listener, an icy feeling in the surrounding atmosphere, as well as a physical feeling of a cold grip on, or brush against the observer's flesh. There is also a high pitched humming sound, or the Singing as it is sometimes called, which is associated with Ben MacDhui and the Grey Man.
Additionally, the Grey Man has an extremely powerful psychic effect. Visitors to Ben MacDhui report a feeling of overwhelming negative energy. Occasionally this is described as extreme lethargy and despondency. More often, it is typified by acute fear, apprehension and an overwhelming panic, leading to suicidal thoughts or physical flight from the area. Generally, this fear is accompanied by the physical sound of echoing footsteps chasing the observer, and sometimes the sound of a resonant and yet completely incomprehensible voice which seems to be faintly Gaelic in nature.
The most common place that The Grey Man is on the mountain, but he has also been commonly spotted in a forest near Aberdeen, Rothiemurchus Forest. References of the wild 'Grey Men' date back all the way to the 13th century. Since then many climbers have reported seeing, hearing, or even feeling the grey man. In 1925, a climber by the name of Professor J. Normal Collie reported hearing The Grey Man. He said that for every two or three steps he took, he heard one loud crunch. All the while he was speed-walking at a reasonable pace, but the footsteps were coming closer and closer. At last he couldn't bear it anymore, and sprinted away. Another encounter with the Grey Man was reported in the forest near Aberdeen. Three men were walking and reported seeing a large creature that looked like a man, but had an eerie, inhuman face. A couple weeks later, The Grey Man showed up, and chased their car, trying to get in. He chased them a short distance, but went up to 45 miles per hour.