
See Dragons and Wolves for more info
A dragon is a guardian of relics and secrets. And in the ancient priesthood, they were guarding the knowledge of the mysteries.
δρακον and δρακαινα
II. the constellation Draco, Arat.46, al., Man.2.69.
III. a sea-fish, the great weever, Epich.60, Arist.HA598a11, Hp.Vict.2.48.
IV. = κηρύκειον, prob. a wand with a serpent coiled round it, S.Fr.700 (cf. 701).2. serpent-shaped bracelet or necklace, Luc.Am.41.
3. a noose or crossed bandage for the ankle, Heraclas ap.Orib.48.5.1.
4. dragon-standard, Lib.Or.1.144, Them.Or.18.219a, cf. Or. 1.2a: hence, corps of 1,000 men in the Parthian army, Luc.Hist. Conscr.29.
II. scourge, Ar.Fr.767.
Comes from derkomai (δέρκομαι) or drakein (δρακεῖν) meaning to see clearly
2. c. acc. objecti, look on or at, Il.13.86, etc.; “τί . . ἥδιον δρ.;” A.Ag.602; “ἐδέρχθης ὀλιγοδρανίαν” Id.Pr.547; so “δ. εἴςτινα” Hes. Sc.169, E.HF951; “κατά τι” A.Pr.679; descry, perceive, Od.10.197, E. Andr.545; “κτύπον δέδορκα” A.Th.103(lyr.).II. of light, flash, gleam, like the eye, δέδορκεν φάος, φέγγος, Id.N.3.84, 9.41; δεδορκὸς βλέπειν to be keen-eyed, Chrysipp.Stoic.3.198; “τὸ σφοδρὸν καὶ δεδορκός” Plu.2.15b. (Cf. Skt. dadárśa 'have seen', dṛ[snull ]tás 'seen'; prop. not merely of sight, but of sharp sight, cf. A.Supp.409, S.Aj.85.—Poet. and later Prose.)b. look with favour on, of Destiny, Pi.P.3.85.

The writers of the Greek New Testament,
who studied exclusively the Greek Septuagint,
knew that...
The Ophis (serpent) in the Genesis Paradise account was indeed a Drakon (δρακον):
καὶ ἐβλήθη ὁ δράκων ὁ μέγας, ὁ ὄφις ὁ ἀρχαῖος, ὁ καλούμενος Διάβολος καὶ ὁ Σατανᾶς, ὁ πλανῶν τὴν οἰκουμένην ὅλην· ἐβλήθη εἰς τὴν γῆν, καὶ οἱ ἄγγελοι αὐτοῦ μετ᾽ αὐτοῦ ἐβλήθησαν.
And the great drakon was thrown down, the ancient ophis, the one called Diabolos and satan, the one causing the whole inhabited world to wander; he was thrown into the earth, and his angeloi were thrown with him.
Here in Revelation, the apostles are telling us that "the ancient ophis" is "the great drakon".
We know what wandering means...
The dragon is the temple guardian, guardian of relics and secrets. The dragon will initiate you.
The writers here are salty that the drakon was initiating the public.
People in the cult do call the Ophis "diabolos" or "satan" (though Genesis doesn't), people do conflate them.
Angeloi in the Ancient Greek language means "messengers" (literal Greek translation), which we can take to be the temple guardian's attendants...
he was thrown into the earth, refers to the Morning Star / Eosphorus story in the Greek Septuagint.
Later that Morning Star is translated into Latin as Lucifer.
Implies that the Eosphorus/ Lucifer (Morning Star) was a Drakon as well... the Drakon is a dawn bringer.
We see torch-bearer (medea, hecate, ceres, etc; guidance in the rite; e.g. eleusis torch carvings) and dawn bringer traditions (TODO: give examples) in the ancient Hellenic world.
See Genesis