Through some legends of western dragons and the associated ceremonies, the author searches in the symbolic of the snake the significance of this image, in order to suggest a new interpretation: a profane image of the running water illustrating its mechanism and maintaining the conscience of the floods within society, while exorcising its anguish by the feast and the mask. In conclusion, the author points out the part of images, with the scientific concepts and theories, in the pedagogy of the environment and the relationship between man and the environment.