In important ways, the following represents data gathering but not necessary evidence gathering. In other words, the two examples of divining snakes cited below need not have anything to do with each other or with a central interpretive thesis regarding Genesis 3 that I’m working on. That said, they are both abnormally interesting.
First, this from the Iliad (II:303-335). I copy Murray’s 1924 translation because it is easy to copy.
It was but as yesterday or the day before, when the ships of the Achaeans were gathering in Aulis, laden with woes for Priam and the Trojans;  and we round about a spring were offering to the immortals upon the holy altars hecatombs that bring fulfillment, beneath a fair plane-tree from whence flowed the bright water; then appeared a great portent (μέγα σῆμα): a serpent (δράκων), blood-red on the back, terrible, whom the Olympian himself had sent forth to the light,  glided from beneath the altar and darted to the plane-tree. Now upon this were the younglings of a sparrow, tender little ones, on the topmost bough, cowering beneath the leaves, eight in all, and the mother that bare them was the ninth, Then the serpent devoured them as they twittered piteously,  and the mother fluttered around them, wailing for her dear little ones; howbeit he coiled himself and caught her by the wing as she screamed about him. But when he had devoured the sparrow’s little ones and the mother with them, the god, who had brought him to the light, made him to be unseen; for the son of crooked-counselling Cronos turned him to stone;  and we stood there and marveled at what was wrought. So, when the dread portent brake in upon the hecatombs of the gods, then straightway did Calchas prophesy, and address our gathering, saying: ‘Why are ye thus silent, ye long-haired Achaeans? To us hath Zeus the counsellor shewed this great sign,  late in coming, late in fulfillment, the fame whereof shall never perish. Even as this serpent devoured the sparrow’s little ones and the mother with them—the eight, and the mother that bare them was the ninth—so shall we war there for so many years, but in the tenth shall we take the broad-wayed city.’ On this wise spake Calchas,  and now all this is verily being brought to pass. Nay, come, abide ye all, ye well-greaved Achaeans, even where ye are, until we take the great city of Priam.” So spake he, and the Argives shouted aloud, and all round about them the ships echoed wondrously beneath the shouting of the Achaeans,  as they praised the words of godlike Odysseus. [emphasis added]
Humm. The “great portent” or perhaps better, the “great omen” (μέγα σῆμα) is more than just the snake (δράκων); it is the snake’s activity. And this snake (δράκων) is maybe more than just a snake (όφις), “serpent” may indeed be the correct translation. Notice, however, that Robert Fagles in his 1990 translation renders δράκων “snake” here. Is this in anyway related to what I see as the divining snake of Genesis 3? I don’t know but the Homeric reference is sure to appear in a footnote.
One of the things that drew me to this Homeric omen is that it is part of an extended misrepresentation, not necessarily to say lie, on the part of Zeus. Zeus’ misrepresentation comes first to Agamemnon as a dream. The snake omen then reinforces the divine misrepresentation. In Genesis 3, the snake contradicts a divine misrepresentation.
While you’re thinking about the Homeric snake omen, think about this from Shumma Alu ina Mēlê Shakin tablet 23, line 60:
DIŠ MUŠ ina É NA GAZ-ma KU2 ŠUB-ti3 EN KA-šu
If a snake kills and eats in a man’s house – downfall of his adversary (EN KA-šu = bēl amitišu).
Here his adversary (bēl amitišu) is a court litigate and not a military adversary as we see in the larger context of the Iliad passage.
Again, do I think this omen has anything to do with either Homer or Genesis 3? No, not exactly. Even if neither has anything to with Genesis 3, both omens do reflect some common human dimension that can’t be easily dismissed either. That dimension need not be Freudian or Jungian or Levi Straussian. It also need not be historical (“intertextual” very broadly speaking). That human dimension might just be what Dennett calls “a good trick.” Of course, Dennett is referring to evolutionary biology but the concept need not be limited to that. If these two examples of omens are but good tricks, they are not evidence for my theses even if they may be evidence for Dennett’s.
PS: If one tried to compile a list of divining snakes, it would be very long indeed.