Another short passage from ACC 119, f. 348v (cf. this post) is a scholion on Scylla and Hydra, unrelated to the surrounding texts.
So it reads,
Գի՛րք ասեն սիկղ՛ եւ հիդրայն ծով<ա>յինք սիկղ՛ն շու՛ն ասի գ գլխի եւ հիդրայն չար եւ՛ս քան զնայ
- ծովային adj < ծով, -ուց sea
- շուն, շանց dog
Books say Scylla and Hydra are sea-creatures. Scylla is said to be a dog with three heads, and Hydra to be more dangerous than that.
I have not found in Greek any lines exactly corresponding to these, but for what they’re worth, here are a few loosely related places from Greek literature. (Translations my own.) The following line from Anaxilas (= fr. 22) is quoted in Athenaeus, Deipn. 13.6:
τρίκρανος Σκύλλα, ποντία κύων.
three-headed Scylla, a dog of the sea
The Hydra is canonically described in Ps.-Apoll., Bibliotheca 2.77:
εἶχε δὲ ἡ ὕδρα ὑπερμέγεθες σῶμα, κεφαλὰς ἔχον ἐννέα, τὰς μὲν ὀκτὼ θνητάς, τὴν δὲ μέσην ἀθάνατον.
The Hydra had a huge body with nine heads, eight of them mortal and the middle one immortal.
The Hydra is described as ἀμφίκρανος in Eur., Her. fur. There (1274-1278) Herakles (also mentioning Cerberus) says
τὴν τ᾽ ἀμφίκρανον καὶ παλιμβλαστῆ κύνα
ὕδραν φονεύσας μυρίων τ᾽ ἄλλων πόνων
διῆλθον ἀγέλας κἀς νεκροὺς ἀφικόμην,
Ἅιδου πυλωρὸν κύνα τρίκρανον ἐς φάος
ὅπως πορεὐσαιμ᾽ ἐντολαῖς Εὐρυσθέως.
Having killed the dog with re-sprouting heads all around, the Hydra, Ι completed scores οf countless other toils and reached the dead, to bring to light at Eurystheus’ command Hades’ porter, the three-headed dog.
Hesychius says the Hydra is a water-snake (ὁ ὕδρος ὄφις. οἱ δὲ τὸν χέρσυδρον), and much later a specific description as “wicked” we find in Joannes Tzetzes, Chil. 2.36.263,
Καὶ πεντηκοντακέφαλος ὕδρα τις ἡ κακία.
And a Hydra, the evil with fifty heads.
Finally, the Ps.-Nonnos Scholia (surviving in Greek, Armenian, Syriac, and Georgian) have paragraphs on both creatures: Scholia Inv I 49 (Arm 46 [Manandian, p. 264]) on the Hydra, and 52 (Arm 49 [Manandian, pp. 264-265]), on Scylla. (I hope to offer a post on both of these paragraphs soon.)