Perhaps some dreams might just be indigestion; however, I believe some dreams are a reflection of what is going on in the spiritual plane. Since having my dream about the large cobra in my house, I have been researching Biblical dream symbolism (and many other religions and spiritual practices have their own symbolism/meaning that things in our dreams may be signifying).

At the end of this video, the author concludes that snakes represent our higher consciousness (I think of it as our spirit):

Do you think we sometimes connect with the spiritual world (both good and bad) when we dream?