I think we ought to look at the Word. Job's Leviathan is clearly a dragon. Revelation 12: 9 speaks of the Devil and Satan as that old serpent, the great dragon. Revelation 20: 2 repeats the dragon for Satan and the devil.

I respect the opinions that I've read. It seems, however, as though demons like to claim to be Leviathan, but this is their boss' title.

A dragon is either an animal in the spirit world or what serpents looked like before they were cursed. Serpents now travel on their bellies since they were cursed by God in Geneses.