I thought it was very odd that everyone at the inquest felt so strongly that one of the other characters had killed Moss. I think that's the real clue to what the "Damned Thing" was: the collective animosity of all the characters toward Moss.

I watched the Johnny Quest episode (one of my favorites as a kid) and I don't believe that the eerie sound of the thing was lifted directly from the show. Most likely it was taken from the Twilight Zone, a CBS show that Himan Brown could access for free.

In the days of the Twilight Zone and Johnny Quest there were few ways to produce strange sound effects --no synthesizers before the 70's. But there was an instrument called the melotron --I might be mistaken-- that made a spacey-sounding noise and was used a lot in movies and TV and even in popular and serious music. 