Rav Yaakov Emden's Eight-Legged Camel

On daf 18a of masechet Megillah, we learn the following:

והלועז ששמע אשורית יצא וכו

והא לא ידע מאי קאמרי מידי דהוה אנשים ועמי הארץ מתקיף לה רבינא אטו אנן האחשתרנים בני הרמכים מי ידעינן אלא מצות קריאה ופרסומי ניסא הכא נמי מצות קריאה ופרסומי ניסא:

That is, in the following pasuk, we don't really know what haAchashteranim benei haramachim means:

י  וַיִּכְתֹּב, בְּשֵׁם הַמֶּלֶךְ אֲחַשְׁוֵרֹשׁ, וַיַּחְתֹּם, בְּטַבַּעַת הַמֶּלֶךְ; וַיִּשְׁלַח סְפָרִים בְּיַד הָרָצִים בַּסּוּסִים רֹכְבֵי הָרֶכֶשׁ, הָאֲחַשְׁתְּרָנִים--בְּנֵי, הָרַמָּכִים.

10 And they wrote in the name of king Ahasuerus, and sealed it with the king's ring, and sent letters by posts on horseback, riding on swift steeds that were used in the king's service, bred of the stud;

Rav Yaakov Emden has a rather colorful explanation of just what these animals were. He writes (unfortunately, the text was at the edge of my gemara, so this is a bit smudged):

The smudged Hebrew words at the edge are:
ראיתי
הם
בשתי
על
המרוץ
גם
ידועים
הרמך
ספק
איהו
ע"כ
בני

Thus, to translate to English, the text reads:
"I have seen in the words of the chroniclers of countries that they are still known and found in the land of Persia, and they are a type of camel with two humps on their back (which a man rides between them, just as on a saddle), and they have eight legs, and they are extremely swift racers, and it appears that certainly they were recognized and known to the authors of the Talmud Bavli (and so too it is apparent that they were known to the Tanna of Eretz Yisrael, as is written (in Kelaim perek 8 mishna 5) {Mishna:} "The Ramach is permitted" -- they are achashteranim benei haramachim.) And without a doubt, the gamla parcha mentioned many times in the gemara is one of them. If so, that which they said {in the gemara} "do we know?", perforce the explanation is that we don't know the words achashteranim benei haramachim, to know why they were called by these names {J: that is, their etymology}, what language they were coined from and what their implication is."

Now, we know that there is no such thing as an eight-legged camel, and I would guess that there couldn't be an eight-legged camel. As Rabbi Gil Student wrote on Hirhurim when he discussed achashteranim:

R. Yaakov Emden, in his glosses to Megillah 18a, says that he saw in Persian history books that this is a unique breed of camels with two humps and eight legs, that run very quickly. I'm not sure what books he was reading.

Heh.

Can we identify what sort of camel Rav Yaakov Emden was discussing? I think we can. I believe he was referring to the Sarabha. From Essays on Indo-Aryan Mythology (and thus that of Persia):

Thus, the word Sarabha was used for real animals, such as peacocks, wild buffalos, young elephants, and camel. There is also the "fabulous" Sarabha, which is ashtapad, having eight legs, four of which are upward.

I don't know if in any of these texts, it is both eight-legged and a camel. It is certainly possible; it is also possible that Rav Yaakov Emden was relying on some text that conflated the normal Sarabha, a camel, and the fabulous Sarabha, which was eight-legged. Or else it spoke of Sarabha in different contexts and Rav Yaakov Emden put two and two together.

Here is a dictionary entry in a Sanskrit-English dictionary for Sarabha. What does the Sarabha look like? Here is one depiction, to the right. I don't think it used the extra four legs to run. They were facing upwards.

I think, therefore, that Rav Yaakov Emden was misled, and that this creature is surely not the same one as in the pasuk in Esther. This is one of the pitfalls of Torah UMaddah -- where the madda fails, the peshat fails as well.

He is likely on the right track, though, in saying that this is some sort of camel. After all, the typical Sanskrit word for camel is ushtra. Compare with achastranim. This is therefore likely some sort of fast camel, bred for its swiftness.