I got two for you!
The first one, my hairdresser told me the last time I got my hair cut. She told me that she had been taking some medication to help her stop smoking and that she knew one of the side-effects were vivid dreams...
In her dream, she was fighting a shape-shifter that she described as having taken on a Chucky-doll/ clown appearance. (Classic, I told her.)
While fighting this creature through her house, she remembers it jumping up onto a table. She seized the opportunity to reach out and grab it and she managed to wrestle it to the ground. As soon as she had it pinned beneath her, she reeled back to strike at the creature.
She heard the creature whisper, "I'm going to hurt you where it hurts the most."
In her hand, there were then a pair of scissors, poised as if ready to stab the beast through the heart. She felt her arm begin to swing down with brutal force.
She blinked.
Her fist and the scissors' blade hovered inches above the heart of her two year old child.
She stopped taking those medications...
Secondly, my dreams. Mine tend to be either wild and fantastical and silly or mundane... but ominously terrifying. And I can't tell you why they are scary. If I described them visually, nothing would seem that scary to my understanding ... it's just the fantastical dream was touched with some waking world stress that my brain lost control of and it slips into my REM sleep time and the dream goes from 'disney's alice in wonderland' to 'salad fingers' in a snap.
For example: I dreamed I was in a canoe on a familiar lake and then out of nowhere a man-whale (literally) starts swimming towards me like a dolphin - with a blank expression - coming closer and closer with each breach of the water. I wake up when he jumps up right before my canoe and stares me dead in the eye.
OR in another dream, my sister, a friend and myself managed to find a secret network of hallways in my childhood home that led to a secret game room. The maze was in between the walls of the house so you had to squeeze into it and the entrance was difficult to open and a bit surreal. In my dream, my mother comes home from work and I rush out to tell her about the secret room but in the process, my sister and friend get stuck inside the walls and I can hear them going the wrong way through the maze. The dream ends when I realize they are lost in there and they won't ever be able to come back out.