James Rummel is afraid that some people might confuse him with the Scottish monster Big Gray Man:
But there’s far more than that to Ben Macdhui. The mountain is the reputed home of a vile and terrifying man-beast: the Big Gray Man, as it has become infamously known. Indeed, while on Ben Macdhui, witnesses to the phenomenon known as the Big Gray Man describe how they have variously encountered footsteps, a sensation of a “presence,” occasional sightings of a large humanoid creature, and an overpowering sense of panic.
I should add that Big Gray Man should not be confused, either, with the "Little Grey Man".