Well, we do have lots of evidence suggesting the contrary for some.

Dragons - The odds are dragons are an interpretation of dinosaur fossils.

Sasquatch - There have been to many sightings, from to far back , from to spread out to totaly discount this as lain myth. Yet concidering weve destroyed half the worlds forests, youd think wed have at least one pioece of indesputable evidence ( even an unknown prmate hair sample, unkown rimate fecal sample.... Yet the evidence isnt quite circumstancial either..... Out of anything on this list, sasquatch has the most likleyness of being eral.

Faries/elves/brownies etc - Im not to sure about these. All cultures speak of "nature spirits", which is all these are just in celtic understanding. I think something takes care of the woods, whether its a manifestation of our psyches or not.

Unicorns/peguses - Stricktly myth. I cant exactly remember the mythology, but as far as pegasus, its jstu a constallation, that was written down in a few mythologies ad different things. Unicorns.... Ive never been to sure abotu them, but if they were as wide spread as the mythos say, wed have found SOMETHING, a cave painting depicting them being hunted or something.... Then again the same goes for all of these...

Greenslade, its very simple... has anyone else that you know seen you riding along on dragon back? Ive "met " manythings but they are jsut a dream. Does that mean they are real or not? Depends on your definition of real.... You probably have seen them as most ancients have seen them, in their subconcious. They arent physicaly real, but that doesnt really make them fake. Its no different from god ( monothesitic sence), theres really NO proff at all, that god, or even jesus lived, yet a billion people still follow that path....