Has anyone out there ever experienced this? On two occasions, I have had dreams where I swear I could feel the presence of another sentient being in my dream. I only vividly remember one of the two. I was in the midst of a lucid dreaming state, and suddenly I felt something grab my dream-feet and drag me across the floor of the apartment I was standing in in the dream. I was being dragged at a tremendously fast pace, and could see rows of flourescent lights going past above my head. I could, somehow, just tell that this thing dragging me was not a figment of my own head, but an intruder into it. I felt like I had to wake up or struggle or I would have been literally stolen away - fortunately I did wake up. I fear what would have happened to me if I had not.
I know I had this happen once more after, but it was a less menacing presence - just remember waking from another dream with the knowledge that someone else had been 'in' my head.
I also have experienced sleep paralysis on many occasions, but this was entirely different from that.
Has anyone experienced this before, or does anyone have some kind of theory as to what this was?