Back when I was a teenager, some buds and I had the use of a cabin outside of Markleeville, Ca. This particular cabin is small but had (and still has, i guess) a loft, which is where I was sleeping after a long day of hiking and fishing. Perhaps about 3 am, I woke up, although it was quiet and nothing was amiss that I noticed. I decided, after laying there awhile, that it was as good a time as any to get up and visit the bathroom. As I was heading for the stairs, I sensed something, a lessening of the moon light coming into the room. The moon was full, and the loft had been actually quite well lit by the moon light coming in from the small window.
I turned instinctively to see why the room had suddenly darkened, and saw the outline of a huge head at the window, only a few feet from where I was. Recall that this was a second story window, and you can imagine my surprise and disbelief at what it seemed I was seeing. I couldn't see anything but the outline of the head, no glowing eyes or anything, but I could distinguish hair all around it. Whatever it was let out a huffing sound as soon as it realized I had turned and was looking at it, and then it moved away from the window and disappeared.
I was so surprised and dumbfounded by this experience, that I just stood there for some time, probably a short time, but I wasn't keeping track. There was no way I was going to go over to the window and look out, as I knew that whatever that was shouldn't be allowed to get any closer to me. After a bit i pulled myself together, and I hurried downstairs, woke up my friends, and turned every light on in the cabin. They didn't know whether I was serious or pulling their legs, but as a group we eventually got some flashlights and all three of us went outside and looked around. The only thing we could find that night, or the next day, was some scuff marks on the ground around the back side of the cabin, but no clear footprints or anything, as the ground was either hard packed earth or rock.
Now I can't say exactly what it was I saw that night, as I only saw it for a few seconds, and then only in outline, but it wasn't a bear that was looking in the second floor window at three in the morning. My fishing was over for that trip, and it definitely creeped me out later to consider the relatively remote sections of creek I had been fishing alone the day before. I have never had an experience like that since, and hope I never do.