
That is probably what made me conclude that. Power to dominate human minds was elsewhere seen in Ainur (Morgoth, Sauron, One Ring - which is basically a portion of Sauron's soul, Saruman), so the fact that dragons have similar ability would suggest that they are of similar nature.I'd need to check. I don't recall reading anywhere the dragons were spirit-filled... just corruptions, bred and fed and nurtured to become the monsters they became. And yet... how did at least the one of them get the hypnotic eye power he was given, if not from some source other than a gigantic worm?
You are not:I'm sure I remember in The Children Of Hurin that Glaurung 'spoke by the spirit that was in him', or something along those lines (I might be completely mistaken however).
And now he stood alone, for the few that had followed him had fled into hiding. But in that moment Glaurung the fell issued from the gaping Doors of Felagund, and lay behind, between Túrin and the bridge. Then suddenly he spoke by the evil spirit that was in him, saying: 'Hail, son of Húrin. Well met!'