I used to suffer from night paralysis, where you wake up but your body doesn't, so it kind of feels like.... well, paralysis. I've known some people describe it as what they imagine being possessed feels like, and if you're waking up from a bad dream that involves the supernatural or anything like that (I have once), then I get what they mean.
That's not the weirdest one though. One time (thankfully only one time thus far) it "upgraded" to a night terror. I remember I was dreaming SOMETHING, but I can't remember the details of the dream itself. All I recall is that I was overcome by a feeling of horror and sadness, and I let out a series of screams. 3 of them, to be exact.
When I woke up, it took me a moment to realize where I was, because I was standing in the middle of my room. There were a few seconds where it felt like I was between being asleep and being awake, and I wasn't sure where what I was dreaming ended and what was reality began. So I stumble out into the hallway outside my room only to find out that the screams had been real and I woke the entire house and scared them since I've never screamed like that before.
It was a really weird way to wake up. As much as it sucks to wake up in a bad way though, it's worse when you realize you've woken everyone else up too.
Also, I used to get charley horses in the middle of the night too, and waking up to what feels like your leg imploding on itself is not my idea of a good nights rest, to say the least.