Encounter With a Shape Shifter

Phantoms & Monsters has this great post from their mailbag about an "Encounter With a Shape Shifter":

I was with a group of people on Saturday, August 8th in Central Arkansas (out in the country) right before dusk. This area has one lane bridges with gravel roads and no road name signs. Many years ago this had been a Amish community. One of the people I was with had lived there when she was a child. We had returned to the area to go ghost hunting at a cemetery near her old home. None of us are drinkers or drug users and are all middle aged. We belong to a local ghost hunter's club, but this night, we were on our own.

We arrived well before dusk to make sure we had a good feel for our surroundings. I stepped out of the car and walked maybe 6 feet when I heard the sound of something quickly approaching me. It sounded like wings flapping, but not the same. Hard to describe really. It was on a much larger scale than I had heard before. I quickly turned around and saw this thing headed right for me. I was so scared I could not image what I was seeing. I screamed and hit the ground. It flew over my head and landed on the tree limb near me. I looked up and saw it looking down at me, I turned as my friends called my name and was running to me. When I looked back, I couldn't see it. My friends witnessed it as it flew towards me though they didn't see it in the tree.

It didn't look the same in the tree that it had looked while flying toward me. In the tree, it looked more like a large worm or snake but much, much larger. It looked as if it had wrapped it's self around the tree limb. A bird can't do that. I did look to see if there were any other reports like this area, but did not find any documented. I am now afraid to go outside before dusk in fear of seeing another one. I have never been scared ghost hunting. This thing was the most amazing, scariest thing, I have ever seen in my life. I pray I never see it again. Do you have any idea what this thing was? A shape shifter or a Thunderbird maybe? Or a demon? I have no idea.