I dreamed that I was bitten by a cobra, and the venom flowed all over my body, asking the master to interpret the dream.

There are two explanations. One is that you recently read a book or movie about snakes and reconstructed the scene in your dream. Snakes don't come out in winter, so I don't think you will meet them in your life, even in the south. The second possibility is that when you sleep, something sticks to your feet, which makes your feet feel a pain. Because people are in a relaxed state during sleep, slight pain will be perceived by the brain, and when dreaming, the brain will automatically fabricate a picture of being bitten by a snake, which is the performance of exogenous dreams. Furthermore, exogenous dreams often suggest some diseases. What you need to care about is not looking for a fortune teller, but whether your body is unwell, because minor diseases with active brain during the day may be ignored, but you can feel them in your sleep.