“Mercurii Germen”, or the Mercurius seed, lays on this wet dragon, which represents our Primitive Mercurius. As well as Hermaphrodite, because of its fixity-volatility features (10), that’s to say active and passive agents are already within it. The biting tail is here an allegory for continuosly self repeated fixed-volatile actions (11).
https://www.labyrinthdesigners.org/alchemic-pictures/cabala-mineralis-or-the-she-horse-on-urine-work-part-1/2/
"There existed long ago in Tibetan, Indian, and partly also in Chinese Buddhism the idea that the religious practice of meditation serves the goal of producing within the still-living and mortal body the diamond body into which you move, so to speak. Already in this lifetime you use your diamond body more and more as a dwelling place, so that at the moment of death, like a skin which falls off from a fruit, this mortal body falls away and the glorified body -or in Eastern language, the diamond body- is already there. The glorified body, a sort of immortal substance as carrier of the individual personality, is already produced by religious practice during one's lifetime. This same idea, which is strange to official Christian teaching, does come up vigorously in alchemical philosophy. The alchemists, too, strove from the beginning to produce such a glorified or diamond body, and Christian alchemists from the beginning identified it with the glorified body. In order to build up this glorified body, called the philosopher's stone, you must repeat the whole process of creation.“
— Marie-Louise von Franz