Hey, Lee--
I am fascinated by snakes, while at the same time fearing them. They are such beautiful creatures, yet so alien and unhuman, not to mention lethal (sometimes to people, and at any rate to some animal or another). But off the top of my head, the snakehole metaphor of Jack's description is the only snakey reference I recall from the film; from the story, I can recall none. Can you cite specific instances?
As for Western literature/culture, I know that the Shoshone (or Shoshoni) Indians were/are sometimes referred to as the Snake Indians. Sacagawea, of Lewis-and-Clark fame, belonged to this tribe by birth.
Let's get the snake-talk rolling (or slithering!).