I have recently begun an independant study on various mythologies of the world, starting with my favorite -- Greek myths. The more I look into this, the more it becomes evident that those who create myths were and are influenced by the real world around them; superstitions and what not not withstanding.

It has been said that we create myths, legends, and so forth to explain the world around us.

Polycephaly is a great example of this. The hydra, for example. Or cerberus for another.

Relatedly, refer to "holoprosencephaly" ... it's a condition where a creature is born with a single eye centered on the face. There was a famous incident just a couple of years ago where a kitten was born with this very rare condition. It unfortunately did not survive long, but has been secured in recorded history none the less. While it has been argued, quite legitamitely in my opinion, that the Greeks were inspired to create the myths of the cyclops after finding the skeletal remains of elephants, and their heads in particular, it could perhaps be argued that a rare case or two of holoprosencphaly could have only strengthened their case. If not a giant human, why not an animal as well?

I could go on, but will pause for now. I invite comments on this, of course! :)