Epic thunderstorm cloud: Is this real? (PHOTO)

This epic photo of a storm cloud might make you wet your pants with majesty, but is it real? No source information is available at its home on Digg, although one commenter does point out a seeming resemblance to a "huge angry chicken." It certainly looks like it's been Photoshopped. But then again, so does a lot of nature's best work. What are your thoughts?