In this case, scary animals, such as snakes, will appear in your subconscious, which is a representative, so you often watch TV dramas and movies before going to bed, so similar situations will occur. If you often dream about snakes, it means that you often do something when you sleep. This is a very bad thing, so I suggest you turn off the TV or turn off your mobile phone when you sleep, so that you won't think about it and dream about snakes again.