From what I understand, the Annunaki created three specimens with the creatures already here on earth. Zachariah Sitchen showed some clay tablets made by the Sumerians and it shows a big hairy creature that resembles asasquatch. To me that was the first example of of a sasquatch written in history. The other sasquatch creations were probably biological upgrades from the original sasquatch.
That’s only my opinion, I may be wrong.There’s so much we don’t know about our own history, much less about the creatures on this planet.