Inbetween sleep

You know how you wake up in the middle of the night sometimes, usually in a dream-like haze, then you kind of turn over and just fall back asleep? Well i woke up in the middle of the night, and I felt like something, or some energy, was mauling away at my torso. WTF Was that?!
It didn't scare me much, I just kind of went to sleep, figuring it was just a weird dream experience//mini sleep paralysis... but has anyone else experienced something similar?

Actually, I once woke up by the feeling that someone sat on the end of my bed - close to my feet. It really freaked me out. I was suddenly wide awake waiting for any sign what that "someone" will do next. After a while I gathered my courage and turned on a flashlight directed at the place the person was supposed to sit... Nothing. However, it took some time to calm down again and fall asleep.