In the above image, we see Melusine, a feminine spirit, half snake and half woman. Carl Jung spoke of her as an anima figure (CW 13, para 180). Like Melusine, ‘the anima… can appear as a snake’ (CW 9i, para 358). In Alchemical Studies, Jung speaks of Melusine:
In the image above, we see a fresco, circa 1090 C.E. In the image, saints battle a dragon. The dragon, according to Carl Jung, is an archetypal image of the unconscious.
The unconscious is related to the womb and is related to the mother. The unconscious, as great womb of creation, is an image of the unknown depths from which we emerge. For some this is a frightful image: as darkness, emptiness, the void, or abyss. Christian images and Western myths which depict the dragon often represent an ambivalent view of the great mother womb. The dragon resides at the edge of the darkness: gatekeeper to the dark recesses of the unknown.
The Western dragon is readily related to the Western hero (or hero-saint as depicted in the image above). The Western hero desires to defeat the monster of darkness. Jung writes: “The hero’s main feat is to overcome the monster of darkness: it is the long-hoped-for and expected triumph of consciousness over the unconscious.” (CW 9i, para. 283)
Carl Jung says that “the mother image “can be attached to … various vessels.” 
In alchemy, the vessel offers an imaginal space for transformation. The alchemist used vessels to carry out their alchemical operations. It was in such vessels that distillation and transformation occurred, making them a suitable image for the transformation and distillation of spiritual energies.
The above image is an alchemical drawings of the Rebis Hermaphrodite from the The Rosary of the Philosophers, published in 1550. We see the Rebis, as a winged hermaphrodite. The rebis has a male head on its right and a female head on its left, and holds a coiled snake in the right hand and a cup containing three snakes in the left. The Rebis appears to stands on serpents. Notice that the flowers have faces and a bird feeds its young.
“I am up in the hills and looking for a place to camp. The hills are golden-colored, rolling, as you would find in Northern California. I am walking along the hilltops for a while and then I come to a cave. I peek inside the cave and I see a little old hermit. I say to the hermit, “Hello.” And I ask, “Is there a place to camp up here upon the hilltops?” The hermit says, “No!” I look around and I say, “But there is so much room up here in the golden hills.” Then, as I am looking around, I see that at the entrance of the cave, there is a hill and the hill is the head of a huge snake. I shift my perspective and look into the distance: seeing that this snake spans into the distance, running for many miles over the hilltops.”
In the dream, we find the image of cave. In the Upanishads, a cave is found in the depths of the heart. In there, in the cave of the heart, the cosmic Self is discovered. The Katha Upanishad (1.11-13) says “he [the cosmic Self] dwells in the cave [of the heart] of all beings.”