I was outside at 19:40 letting the dogs out. There was a bad storm on the way. My son and I looked up and noticed there was a think black cloud under the higher gray clouds. The black cloud formed into a bat shape and looked like it was made of black smoke webbing. It was completely different from the other fluffy light gray clouds above it. Directly above our house, no higher than 600 feet, there was a very long dark gray/black swirly cloud. It looked like a football stadium long dragon with a fish tail, it undulated from side to side. On its sides were long silver smooth strips that looked like vents. There was a large round area 3/4 towards the end which had a circular opening in its center. When I looked up into the hole I could see light gray clouds above. The longer I watched, the more paranoid I started to feel. My dogs got very agitated. I went inside to get my cellphone, but it didn't record. Whatever it was, it seemed to be organic. It reminded me of those long dragons you see in the Chinese celebrations. The larger portions looked webbed. Very freaky. At first I was in awe, but when the circular opening was directly overhead I got a horrible sense of panic.