The idea of mysterious large humanoids living in the wilderness has been around for quite a while.
http://www.ancient-origins.net/unexplained-phenomena/there-archaeological-evidence-bigfoot-part-i-005350
The earth has harbored various kinds of life forms since prehistoric times.
http://mysteriousuniverse.org/2016/03/the-weirdest-cryptids-that-turned-out-to-be-real
