Ectoplasm (paranormal)
Ectoplasm (from the Greek ektos, meaning "outside", and plasma, meaning "something formed or molded") is a term coined by Charles Richet to denote a substance or spiritual energy "exteriorized" by physical mediums. Ectoplasm is said to be associated with the formation of spirits; however since World War II reports of ectoplasmic phenomena have declined and many psychical researchers doubt whether genuine cases ever existed.
Read more about Ectoplasm (paranormal): Phenomenon, Ectenic Force, Fraud