You have to be old, but if you remember the tv show “The Invaders”, it was about aliens living among us. When one would get killed, it would disintegrate so as to avoid leaving a body.
I submit that Bigfoot is an alien with that capacity. That’s why no bodies have ever been found. :)
I have “The Invaders” series on DVD—great stuff—two seasons.
https://www.amazon.com/Invaders-Seasons-1-2/dp/B001HUHBBS
“The Invaders” a classic QM Production.
I have a copy of the series soundtrack in addition to the DVDs.
Leprechauns too. Never found one of those, have we?