Shadow beings exist. Read one persons account below.
..."just wanted to tell you what I saw one recent night. I was out in my backyard, sitting a little bit off my back porch. It was warm, but there was a really nice breeze that night. I had shut off our outside security light, and I was just sitting in a lawn chair, enjoying the breeze. It was around 11:30 at night. Our next door neighbors are on vacation, and I've been watching their house for them. They live on the corner, and there is a street light at the edge of their property that lights up their yard really well. The only part that is mostly dark is the side of their detached garage. The streetlight is so bright that even with my security light off, it lights up half of our property. (We have a double lot.)
I was looking at the sky, when I noticed something moving out of the corner of my eye. I saw what I thought was a person squatting down, then getting up and moving around my neighbours trash cans that are on the dark side of the garage, towards my home. I watched for a few minutes as what I thought was a person kept moving around. I had my cell phone, and I pulled up the number of the local police department so I could call them if this person looked like they were out to rob my neighbours. The shadow began moving, and it went past the garage into the light I realized with horror that there was no person attached to the shadow, it was just a big black shadow. It was much larger than a real man would be, around 7-8 feet tall. (Our neighbour is 6'6, and I see how tall he is up against his garage, and whatever this was at least a foot taller than him, maybe a bit bigger.)
I gasped out loud, and it turned towards me. I was so scared that I couldn't even move. The shadow suddenly started lurching through the neighbour’s yard, like it was coming for me. I jumped up off the chair, got tangled in it and fell. I glanced over at this thing as I tried to get up. It seemed as if the noise stopped it for a second. I jumped up and ran right into the house. Our door has a window, and as I was shutting the door, this shadow thing appeared in the yard right next to the overturned chair. It stood there for a few moments, and I swear it was actually looking at me, even though it had no facial features. Then it suddenly took off, and vanished from the part of the yard I could see. My husband died 4 years ago, and I live with my 14 and 19 year old daughters. They were watching TV, so I snuck past them upstairs and looked out all the windows. I didn't see this thing anywhere in the yard. I stayed upstairs for a while because I knew by looking in the mirror that I looked like a crazy woman and I didn't want to scare my daughters. I didn't tell them what I saw, because I didn't want them to be scared too. I didn't sleep much that night or last night either! I don't know what this was, but it scared the heck out of me!" Source