How can we see the unknown?

Have you ever wondered how we know what an alien looks like or a Sasquatch? I think we all have a mental picture of these creatures from T.V or movies. How do we know if an alien is green? How do you know a Sasquatch is a big hairy monster? It is made by made up events that are made to look like the real thing. Such as the Roger Patterson's Sasquatch video - it has confused scientist and paranormal investigators for years. It has not been proved to be fake or real. So how do we know what the unknown looks like? Sasquatch was orginated from the North Amercian Natives, They called it a BIG HAIRY BEAST! There has been 205 fake sightings in Canada and the United States since 1905. Has there ever been an alien spotting? In spite of there being as many reports of sighting them as there used to be of elves and fairies, there have actually been no real discovery of aliens.