H. Southern Iraq (Babylon)
What they actually are is explained by Revelation 18:1-2: After these things I saw another angel coming down out of heaven, having great authority; and the earth was lightened with his glory. And he cried with a mighty voice, saying, Fallen, fallen is Babylon the great, and is become a habitation of demons, and a hold of every unclean spirit, and a hold of every unclean and hateful bird.
This picture of continual burning and smoke will be a place of confinement for many demons during the Kingdom Period. It is clear from Revelation 9 and other passages that demons have animal-like features, and this is what the animals of the Isaiah and Jeremiah passages actually represent.