A threat, hidden or named
A snake can represent something — or someone — you sense is a risk, especially if it is concealed in grass, under furniture, or strikes by surprise. This reading fits when the dream is tense and the snake feels adversarial. It often points to a low-grade distrust you have not let yourself fully acknowledge.
Transformation and healing
Because snakes shed their skin, they have symbolized renewal across cultures for millennia, and the snake-entwined staff remains the sign of medicine today. A calm or shedding snake can reflect a transformation you are moving through — leaving an old version of yourself behind. The same image can frighten or reassure depending on where you are in the change.
Let the feeling decide
Snakes are the clearest case for trusting the emotion over the symbol. The same snake means very different things if you wake relieved versus afraid. Notice what you felt, where the snake was, and what it did — that is the interpretation, more than any fixed 'snake equals X.'