The Tempter as shapeshifter

1. One of the oddities of Gen 3 is how the Tempter is introduced with so little exposition or backstory, as if the original audience would be familiar with a character like the Tempter. The name of the Tempter is a pun or triple entendre, so it has a dual identity. There's the image it projects and then there's its true identity. This suggests the Tempter is an entity in the tradition of shapeshifters. Agents that alternate between identities. Agents that may appear to be animals but that's not their true identity or original identity. Conversely, agents that appear to be human, but they've undergone a transformation. 

2. The tradition of shapeshifters is ethnographically quite diverse. Two standard academic monographs are Montague Summers, The Werewolf in Lore and Legend (Dover 2003 reprint) and Sabine Baring-Gould, The Book of Werewolves (2002 Blackmask Online). There's also American Indian folklore about skinwalkers and totemic animal spirits among Plains Indians, desert southwestern tribes, as well as Algonquian tribes (e.g. Manitou). cf. https://www.youtube.com/watch?v=8ae_Xw8IlW8

3. Shapeshifters are naturally impossible, but within the worldview of Christian supernaturalism and pagan witchcraft, they may be realistic. It's necessary to sift evidence for shapeshifters from different phenomena:

i) Orphaned feral children misidentified as werewolves

ii) Lycanthropy as a psychotic condition (e.g. Dan 4). 

iii) People who aspire to be animals (e.g. (Berserkers). They may aspire to be possessed by an animal spirit or actually be transformed into an animal. That, however, is a kind of playacting. 

iv) Distinguishing folkloric shapeshifters from literary and cinematic shapeshifters. 

4. The role of magic also requires sifting:

i) Witchcraft spawns lots of mythology and legend that have no basis in fact. Ingrown folklore that's passed on. 

ii) Defamatory accusations of witchcraft. 

iii) Conversely, cultivating a reputation for witchcraft can have propaganda value by making the individual an object to be feared and placated. 

iv) A distinction between having the ability to be shapeshift and the ability to hex others: S. Augustine declared, in his De Civitate Dei, that he knew an old woman who was said to turn men into asses by her enchantments. Sabine Baring-Gould, The Book of Werewolves (5).

5. It may not be coincidental that shapeshifters are often associated with the desert. That's the case in American Indian folklore, and it has biblical parallels. Consider the ambiguous references in Isa 13:21 & 34:14. And the further fact that the Devil tempted Jesus in the desert. 

6. Of even greater potential interest is whether Lev 16:8 and 17:7 allude to goat demons in the desert. Occultic shapeshifters.

This might resonant with to the original audience for Gen 3, because the Israelites were living in the desert at the time Genesis was written. So even though Gen 3 recounts an incident that happened millennia before, the idea of a malevolent shapeshifter may well be a recognizable entity in their experience. 

This also explains the fluid identity of the Tempter, not only in Gen 3 but Rev 12 and 20. An evil spirit (fallen angel) with an animal name and reptilian imagery or symbolism.