Herr Brocken Spectre, I presume

Though a Brocken Spectre sounds [and sometimes looks] like a baddie in a Sherlock Holmes novel (well, at least to me), it is  just a natural phenomenon. It is a shadow caused when an object, such as a walker, casts a shadow upon mist or cloud. This can typically happen when a hiker is walking along a ridge in sunshine with low cloud beneath. Often, a glory, i.e.a coloured ring surrounds the shadow (it is a type of rainbow). In all my years walking in Connemara, I’ve rarely seen one. On the Monday before Xmas last year, I hiked to the top of Croagh Patrick. Though it was a clear day, the wind whipped up a thin ‘halo’ of snow around the summit, creating an almost invisible mist. It was enough to cause the appearance of the spectre, and it kept me amused waving my arms and legs about once I spotted it. Given the right lighting conditions, even I can cast a huge shadow. Another picture here.