I tend to have rather unpleasant dreams, although I wouldn't call them nightmares. Fighting something or being chased is common. One dream I had a few weeks back that stayed with me was being chased around some... hotel, I think. Like, a hotel in a mountain, old-fashioned, with long corridors. I was chased by some... zombie, I suppose, a big rotting man. Then I found an axe, managed to chop off its arms then threw it out a window. It took a while too, felt like hours, as I tend to have rather long dreams. Many times, I don't dream I'm myself, and I also have dreams entirely in third person which feels like watching a movie. Sometimes, I have lucid dreams where I realize I am in a dream, but I still can't really control it but I know that whatever I think will happen, will happen. Sadly, my pessimism causes those dreams to quickly turn into lucid nightmares.
Have anyone else had semi-lucid dreams, where you realize you are dreaming, but then everything starts turning out as you expect/fear they will, outside of conscious control?