Walking Corpse Syndrome

Walking Corpse Syndrome or Cotard’s delusion is a mental condition in which sufferers believe they are missing internal organs, have no blood, or that they are dead outright. PET scans of a patient show that they exhibit brain activity similar to someone asleep or under anesthesia. It's often seen in patients who have severe depression. Cultural beliefs, such as folklore about creatures that take organs or cause deaths in ways that can't be perceived, may also contribute to this rare disorder.