The Brocken Spectre
This particular photo is just one of many wonderful examples of the Brocken Spectre Phenomena out there. This one was taken in Poland's Tatra Mountains, and as you can see, features a shadowy human figure with notably long limbs floating in the sky, shrouded with a rainbow colored aura. But, what appears as a ghostly spirit is actually the product of being in the right place at the right time.
According to Wikipedia:
The "spectre" appears when the sun shines from behind the observer, who is looking down from a ridge or peak into mist or fog. The light projects their shadow through the mist, often in a triangular shape due to perspective. The apparent magnification of size of the shadow is an optical illusion that occurs when the observer judges his or her shadow on relatively nearby clouds to be at the same distance as faraway land objects seen through gaps in the clouds, or when there are no reference points by which to judge its size. The shadow also falls on water droplets of varying distances from the eye, confusing depth perception. The ghost can appear to move (sometimes suddenly) because of the movement of the cloud layer and variations in density within the cloud. The head of the figure is often surrounded by the glowing halo-like rings of a glory—rings of coloured light that appear directly opposite the sun when sunlight is reflected by a cloud of uniformly-sized water droplets. The effect is caused by the refraction of visible light. -WikipediaFirst described in 1780 by Johann Silberschlag, the name comes from the Brocken, a peak in Germany's Harz Mountain range, noted for its misty mountain banks and low-altitude accessibility. Legend has it that at least one mountain climber was so startled by the sudden appearance of a huge, shadowy humanoid that he fell to his death. Since then, it has become a widespread superstition that any climber unfortunate enough to witness a Brocken Spectre, or Brocken Bow as its sometimes called, is doomed to meet his/her demise on the mountain. If you think THAT'S spooky---apparently you don't even need a mountain OR the sun to create a similar phenomena. Check out this ghostly looking image, courtesy of Harald Edens: