Tall Shadowy Figure

This experience took place about five years ago. I was seventeen at the time, and it was a hot summer afternoon. I was in my parent's bedroom looking for some batteries for the T.V. Remote when something felt "off" I don't know how to explain or describe it. I looked up from the drawer I was digging in, and through the window I saw a tall, dark, shadowy, blacker than black figure walk by the window. I watched as it moved quickly past the window.

I wondered at first if it was my grandfather walking by, he lives in a sort of add on apartment and often walks around the house to feed his dogs in the back yard. He's a big and tall dude, but this thing was taller, and it's head was level with the top of the window frame. I ran to the second window on the other side of my parent's bed to see if I could get a better look at who or what it was, but it was gone, and so was the weird feeling I'd had.

I went outside later that night and measured the height of the window, because I'd seen people walk by that window before, and none of them came close to being tall enough that their head was level with the top of the window. The shadow man would have had to have been almost eight feet tall!

I saw this shadow figure again about a week later, but this time it was walking past the large windows of the front room. I got that same weird feeling, but it was gone again in an instant just like the first sighting. I haven't seen it again since that time, though I sometimes will still get that "off" feeling.

After seeing it a second time I decided to tell my brother about it, because he also believes in ghosts, spirits, and the like. He said that he had seen something similar to what I'd described standing outside of his window next to a storage shed we have in our back yard. We wonder if the shadow man is connected to something in the back yard, because both times I'd seen it, it was walking toward the back yard, and my brother had seen it in the back yard.

Any ideas what this tall, shadowy figure might be?