You can thank the Marvel villain Nightmare for all of your nightmares. Basically, he rules terror and fear, and there are no limitations to how scary he can be. This fear he instills helps him gain power over all of reality. He’s able to bend the laws of reality, and those creepy visits in your dream world, where you thought you were safe, are tunnels for him to crawl and slither down to attack. As Nightmare himself puts it, “Mortal fools! I am the Master of the Subconscious, the Midnight Leviathan — proof positive that the most precious of dreams too often fall prey to…Nightmare!” Get ready for a state of horror all thanks to Nightmare, who won’t hesitate to scare you out of your pants. You might never want to sleep again (Quora).