When I was about six, we knocked a fox over on our way home from my aunties during the winter. That night (and many, many nights after) I dreamt that the foxes family turned themselves into envelopes, posted themselves through our letter box, and came upstairs and killed me in revenge. It's weird but I was absolutely terrified that this poor foxes' family would get revenge for what my dad did when he knocked that poor beautiful animal over
As an adult my dreams have been much worse. I have a very vivid and active imagination and have suffered from hallucinations at various intervals. My dreams are always worse versions of my hallucinations. If anyone has seen the Grudge, I dream of that girl coming up under my covers all the time. Also the little boy whose face you see through the lift window on every floor.
I had a dream once where my sister had a cold (she had a cold in real life at the time) and I went into her room to check on her, and she'd passed away. I was terrified and so upset at the thought.
My most terrifying recent dreams have been about Slenderman. Don't know if anyone has heard of him, but whilst I really enjoy anything about Slendy, I find the concept actually terrifying and reading stories about him really fuels my dreams. I'm sure he'll be a prominent figure next time I have some hallucinations
And just for the laugh... Also about Slenderman. I once had a dream that Slenderman was my dad, and I was Slendergirl. We were a team and we killed/stalked/terrified people in typical slender fashion. It sounds really sick, but being on the other side of the slender-ness was actually quite entertaining. Even though I was a murderous mythical being who kept killing people and scaring them and stalking them down streets, I'm sorry to say I actually enjoyed it