'Unclean Spirit' in the Bible

And I saw coming out of the mouth of the dragon and out of the mouth of the beast and out of the mouth of the false prophet, three unclean spirits like frogs;

And he called out with a mighty voice, "Fallen, fallen is Babylon the great! She has become a dwelling place of demons, a haunt of every unclean spirit, a haunt of every unclean and hateful bird.