'...serpent cast out of his mouth water as a flood...'
In my reading today I came across the following that made me think of Revelation 12:15:
"Only those wadis [dry river beds] which are spring-fed retain their streams throughout the year...It is too easy to be deceived by the gentle brooks. The weather is perfect for hiking, and nothing could be more pleasant than wading in the streams rather than walking the tentative route along the cliffs. Yet it is a temptation that should be resisted, for the desert is prone to flash floods of stunning and sudden power. If it rains in the Judean Mountains, a flood can materialize with no advance warning, crashing through the wadis with a force that rips boulders from the hillsides and slices chunks from the asphalt road below. The tell-tale rumble often comes too late for any possible escape, and nearly every year a hiker is carried away by the unpredictable and unforgiving torrent."
(The Dead Sea: Myth, History, and Politics, Barbara Kreiger)