Holy (Unsupported?) Snakes

I’ve been struggling to figure out if Greek ἱερά ever meant snake omen or even just some kind of snake. The exact focus of my concern is a passage in Xenophon’s Cyropaeodia that reads,
Παρὰ γὰρ ἱερὰ καὶ οἰωνοὺς μήτε σαυτῷ μηδέποτε μήτε στρατιᾷ κινδυνεύσῃς (1.6:44)
When I cited it before, I translated it “Never put yourself or your army in harm’s way contrary to a serpent and bird-omen” and then added “or something like that.” LSJ9, 820, renders ἱερά, “serpent” as its first meaning and directs us to Aristotle’s Historia Animālium, 607a31. But LSJ also refers us to ἱερός. This word in its several forms means manifesting divine power, holy, sacred, sanctified, or the like. It is with this meaning that the form ἱερά most often appears.
The Aristotle passage falls just short of being helpful in a couple of ways: “There is a certain very small snake (ὀφιδιον), which some call ἱερόν, which the really big snakes avoid.” I’m not so sure how to take this and despite some effort, I can’t find any examples where a ἱερά is unambiguously a snake or a snake omen. Every example I’ve found either clearly means or might mean sacred, sanctified, or the like. If you, abnormal reader, know of any clear examples where ἱερά means snake or serpent, please tell me of them.
This is somewhat outside my normal abnormal interests and expertise. But it is, or may be, part of a story concerning the ubiquity of certain specific kinds of ancient divination with likely Mesopotamian origins: a story I am trying to weave together.
By the way, if there really are clear examples where ἱερά is some kind of a serpent or snake, another quite intriguing issue comes to the surface.