But that doesn't jive with the " Otter Man " ( and seemingly the most persistant ) version of Kushtaka ..
You might as well claim that sightings of Bigfoot are the basis of all bipedal boogey man stories ..
I see where you're coming from. I suppose what I am positing is that, yes, given that cultures do seem to take things and put their own personal slant on them (making it more "their own" or putting a given creature or place in more in line with their other beliefs, religious and otherwise), I can see where sightings of a "Bigfoot"
could spawn legends of bipedal, hairy boogey man stories. Note that I stated that such sightings
may have inspired such legends. It's also possible that, even if a Bigfoot does exist, that those legends may have come from elsewhere having nothing to do with a Bigfoot sighting. I'm not wobbling, rather trying to stay open-minded and be my own personal skeptic. Hypothetically, if Bigfoot does exist, is it out of the rational realm for it to have spawned not entirely accurate legends from various cultures?
By way of example:
It is generally believed that what sailors thought in ages past to be a mermaid
WP may very well have been a manatee or dugongs. Sailors, seeing what looks to be perhaps a torso and a lower flipper instead created the legend of a half-woman, half-fish being. Now a manatee looks nothing like such a creature, but an elusive sighting tends to get a culture's juices flowing. And what do sailors (predominantly male) miss in their long months at sea? Women. So their culture made the manatee into a swimming woman. Manatees may also have served as the basis for the siren legends as well. Women on a ship was thought to be bad luck, so is it a stretch to associate something feminine and seen in the sea as a bad omen? And, according to Wiki (for what it's worth) mermaid tales are rather universal, but with their own spin on them which suggests a cultural bias.
Is it possible that the manatee inspired some or many of these legends of half-fish people in the water? I don't think that it is beyond the bounds of reason to say so.
So I am basically playing the Devil's Advocate and saying that if there were Bigfoot running around that it would be equally within the bounds of reason for them to inspire legends in multiple cultures.