Myth?

I feel a propper Myth allways needs a certain ammount of enigma. A certain unawnsered ending such as bigfoot or the Yeti. What is it? Where are they? Do they realy exist?
Usually they origionate from rumor and are local to a few areas or certain places. And are rarely seen even in the Myth itself.

They are also a generally accepted truth that is prehaps put into history. The lack of evidence of it's existance helps the enigma of the object/situation continue and thrive as it is mainly the individuals imagination fillin gin the blanks.