Australia has about 200 species of snake, 25 of which are potentially deadly and 20 of the world’s 25 most venomous snakes are Australian. This is a potent, powerful card.
The caduceus, two snakes entwined around a staff is commonly, although mistakenly, used as a symbol of medicine. It actually belonged to Hermes, a god of transitions and boundaries who could move easily between the mortal world and the divine. Some sources also associate Hermes with alchemy which ties in nicely with the key word transmutation.
Transmutation, the turning one thing into another. Perhaps with the snake, this is linked to shedding skin, transformation into a new you or changing energy into matter in a similar way to the court cards in the wands suit of the wild unknown tarot which feature snakes.
I find the image of the caduceus an interesting one from a symbolic point of view. Snakes in general, when stretched out, can be considered a phallic symbol, curled up some say they represent the vagina. Thus the image of two snakes entwined can show us the merging of masculine and feminine. Other dualities the snake symbolises include healing and poison, light and dark, solar and lunar, spirit and mundane, life and death. These polarised ideas hold together to make a whole, to create a balance or equilibrium reminding me of the temperance tarot card.
The single snake around a staff is the rod of asclepius. Asclepius himself was the god of healing and medicine and the snake is said to have a number of interpretations centred around the dual nature discussed above. Another suggestion is around the shedding of skin being a reference to the shedding of illness.
In terms of aboriginal mythology, we see the snake feature in a lot of dreamtime stories as a creator as well as guardian of rivers. Snake teaches that the world is in balance and that taking more than you need will upset this, that you should live in tune with the earth. Just as snake created the land, you can create your own landscape, you have the power of transforming what is in front of you.