My most horrible nightmare was when I was about 9. I was running around in a scary ass underground maze and eventually got  into something like a conference room with monsters sitting around a large, round dining table. What then happens is some other monsters come in with carts with these glass domes for food, except in there are smaller monsters, silently screaming and squirming in fear. They then take these plates and put them in microwave like devices, that merge the smaller monsters into hideous chimeras that are half melting. (I see all this from my hiding spot in a crack in the corner) While the monsters start eating their dinner with silver forks I start feeling cold and sweating at the same time and realize I'm in a dream but can't wake up. Suddenly one of the monsters turns around and looks directly at me, that's when I wake up and immediately run out of my room.