Nachtmahr
A Nachtmahr is a smelly demon that sneaks into your head and shits all over your dreams. You wake up screaming because your brain is full of poop.
My dog was barking at nothing. I looked at him and realized my Nachtmahr was already in the house.
I had a dream about being chased by a giant sandwich. That was my Nachtmahr telling me to eat better.
I woke up crying because my brain was on fire. My Nachtmahr had thrown a party and forgot to invite the fire department.