This is indeed funny, but moreso if you remember from the Bible that the serpent once walked on feet, or at least hands and feet, and was cursed to slither on the ground for his act in tempting Adam and Eve to eat the fruit. This enhances why the name "Crawly" doesn't sit well with Crawly, because he was not supposed to be reduced to crawling. Something I never thought I'd say when reading fiction, but some Biblical knowledge is actually very helpful when reading this novel, and adds to better understanding of events and humor in the book. But we won't get too nitpicky, and everyone will bring in different details from their views, and I welcome this.
So yes, the tempter being called "Crawly" is very funny, and you're right to laugh at it. Thanks for sharing!
I'm glad you noticed the relationship between Crawly and Aziraphale as "drinking buddies," as that will be a driving force throughout the rest of the book. It sounds counterintuitive to everything we are taught in the Judeo-Christian dogma of heaven and hell, but Gaiman and Pratchett suggest here that even the agents of the Almighty and the Lord of the Underworld are not beyond questioning the "ineffable" plan and joining forces to reach their own ends and not their masters'. Good eye, and I'm glad you find it amusing, because it only gets better.
As for the rain, the first paragraph says that rain had not been invented yet, "But clouds massing east of Eden
(does anyone else see the Steinbeck reference here?
) suggested the first thunderstorm was on its way, and it was going to be a big one."
It seems to me here that the first thunderstorm is coming because the Fall of Man has already happened, and thus God will no longer allow it to be nice all the time. The end of the chapter mentions the early thunder rumbles of a storm, and we are told "It was going to be a dark and stormy night," another cliched literary reference we're all familiar with. Thanks for noticing the rain, as I think it is an important element in this prologue.
Also keep in mind Aziraphale's missing sword, and the fire the humans are cowering around at the end of this prologue. This suggests that it is Aziraphale who gives the humans fire (since Prometheus wouldn't be part of the mythos this book is based on), and remember the missing sword, because it will come into play later.
This also gives us the beginning of a notion that the angel is not as angelic as he ought to be, because he gives fire to the humans when he wasn't told to, and that Crawly, questioning whether or not what he did was bad or good, is not necessarily the agent of evil HE ought to be. We are being set up here to question not only the agents of the Almighty and his Nemesis, but also the nature and plan of the Almighty Himself. This, as I have said, is the driving force of the novel, and I think this prologue sets us up very well for the events which are to follow.
Anyone else have any comments or interesting tidbits they noticed?