How very interesting these theories are! I hadn't thought of the portal idea, the UFO thought, or the shapeshifter theory. I would really like to delve deeper into this one. I love Bigfoot stories, and I do believe that he has to exist. My thoughts about never capturing him have been that he is just too smart for the average man, he may have some extreme psychic abilities... and another one of my theories has been that maybe there is something about his bones/body that causes them to disintegrate very quickly, making the possibility of finding remains nearly impossible.
WingsOnite, I will be interested in reading your book, once it is written! =)