I have been scouring the internet for information on the Gigantopithecus. This creature actually existed and it's existence is a theory for the existence of the sasquatch. Personally, in my opinion, it makes sense, but then that's just me. You draw your own conclusions.
Gigantopithecus Blacki is an extinct primate which did exist in Asia approximately 500 000 years ago. There are many theories within this theory. One theory is that the Gigantopithecus retreated into the Himalayas some 500 000 years ago. This creature would be known as the modern day Yeti, or Abominable Snowman. Another theory suggests that the Gigantopithecus crossed the ice bridge over the Bering Strait from Asia to North America during the last ice age. The migration path of these creatures filtered down all the way to South America.
In 1932 a Dutch paleoanthropologist by the name of G.H.R. Von Koeingswa encountered the first Gigantopithecus Blacki tooth, while in a Hong Kong apothecary shop. Over the years a handful of teeth and jaw bones have been found. Most of these discoveries have been in China and India. Skull features are very similar to the modern day gorilla.
There is obviously a lot of information about this theory and it is impossible for me to describe it all. There are Gigantopithecus links in the appropriate section for your browsing. I have provided a link below to the page.