I tend to think that all the "Bigfoot" type of tales are probably based on something but I would agree that there is a strong possibility that people who have seen one of these things are trying to perhaps rationalize what they've seen into something that they can identify. Something furry and immense doesn't remain an "unknown"...it becomes another bigfoot sighting.

We seem to be a species that needs to label things so that they are familiar when we experience the unusual. Any strange lights in the sky become "ufos", a large strange dog could be a "werewolf" and so on. I think we've always been like that. We don't like not knowing what something is.

Stephanie

In every man there is something wherein I may learn of him, and in that I am his pupil.--Ralph Waldo Emerson