The Mad Gasser of Mattoon (also known as the Phantom Anesthetist, or simply the Mad Gasser) was the name given to an event of alleged mass hysteria in which a person or people allegedly committed a series of apparent gas attacks in Mattoon, Illinois, during the mid-1940s. More than two dozen separate cases of gassings were reported to police over the span of two weeks, in addition to many more reported sightings of the suspected assailant. The gasser's supposed victims reported smelling strange odors in their homes which were soon followed by symptoms such as paralysis of the legs, coughing, nausea and vomiting.