Bigfoot is in fact an alien. I know, when I had this epiphany it totally blew my mind too. It makes so much sense though. Think about it for a second. Just let it soak in.
We humans have this preconceived notion that aliens are supposed to have big heads and be green or whatever, but do you really think all aliens would look the same? I don't. I mean it does seem like a giant humanoid figure covered in hair would be a bit primitive, but that's probably just because we've so readily accepted the theory of cavemen and the missing link and whatnot. But what if bigfoot wasn't just an animal? What if a tall, hair covered creature could actually be more intelligent than us?
I'm actually a little surprised no one has ever thought of this earlier. I mean, there have been tales of both aliens and bigfoots for centuries. Maybe these UFO sightings that have been recorded by ancient Aztecs are of UFOs that carried the very bigfoots that many Native American tribes told stories about.
This would actually explain a lot. For instance, it explains why no real bigfoot carcasses have ever been found. It explains why there are so many sightings and no captures of the creature. Maybe these aliens truly believe in the motto "take nothing but pictures, leave nothing but footprints." I wish more people were like that.
So there you have it. I've just made the biggest discovery of the century.