An urban legend:

*Appears mysteriously and spreads spontaneously in varying forms
Contains elements of humor or horror (the horror often "punishes" someone who flouts society's conventions).

*Makes good storytelling.

*Does NOT have to be false, although most are. ULs often have a basis in fact, but it's their life after-the-fact (particularly in reference to the second and third points) that gives them particular interest."

Submitted by Evening