Well, the current pop guesses are demon, angel or Mothman or a Nephilim, some say that it is just a palm tree or well, fill in the blank _____________.
A certain Richard Christianson claims to have taken the photo—full stop here for first skeptical observation: why a photo and not a video? On most devices the option of photo or video is a merely one virtual button push away. A video would take quite a bit more work to fake whilst a photo can just be photo-shopped since it is one image, one frame, one angle, etc.