Cotard’s syndrome is also known as the ‘walking corpse’ syndrome. It is a neuropsychiatric condition characterized by the delusional belief that one is dead, dying, rotting or nonexistent. Nihilistic beliefs range from involving particular body parts to including the entire body and even a denial that the self exists. The condition was first described by French neurologist Jules Cotard in 1880.
A real zombie attack happened during World War I. The battle was known as the ‘Attack of the Dead Men’. Russian soldiers defending Osoweic Fortress from the German army were bombarded with chlorine gas. The surviving Russians charged at the German forces despite coughing up their own blood and lung tissue. The frightening appearance of those advancing moribund Russians scared the German soldiers who turned and fled, some falling into their own traps.