Our Gemara on Amud Aleph teaches us about the end times:

 

וְאָמַר רַבָּה אָמַר רַבִּי יוֹחָנָן: עָתִיד הַקָּדוֹשׁ בָּרוּךְ הוּא לַעֲשׂוֹת סוּכָּה לַצַּדִּיקִים מֵעוֹרוֹ שֶׁל לִוְיָתָן, 

 

And Rabba says that Rabbi Yoḥanan says: In the future, the Holy One, Blessed be He, will prepare a sukka for the righteous from the skin of the leviathan.

 

How can we understand this aggadah? Peri Tzaddik (Succah 11) draws a comparison between this festive meal from the slaughter of the Leviathan at the end of days, and the slaughter of the Evil Inclination at the end of days, described in Succah (52a-b):

 

כדדרש רבי יהודה: לעתיד לבא, מביאו הקדוש ברוך הוא ליצר הרע, ושוחטו בפני הצדיקים ובפני הרשעים. צדיקים נדמה להם כהר גבוה, ורשעים נדמה להם כחוט השערה. הללו בוכין והללו בוכין. צדיקים בוכין ואומרים: היאך יכולנו לכבוש הר גבוה כזה! ורשעים בוכין ואומרים: היאך לא יכולנו לכבוש את חוט השערה הזה! 

 

The Gemara answers: This can be understood as Rabbi Yehuda taught: In the future, at the end of days, God will bring the evil inclination and slaughter it in the presence of the righteous and in the presence of the wicked. For the righteous the evil inclination appears to them as a high mountain, and for the wicked it appears to them as a mere strand of hair. These weep and those weep. The righteous weep and say: How were we able to overcome so high a mountain? And the wicked weep and say: How were we unable to overcome this strand of hair? 

 

To Peri Tzaddik, this slaughtering of the evil inclination is one in the same as the Leviathan. 

 

 

The Leviathan is a primordial foe, representing ancient forces and archetypes that are part of the structure of the material and spiritual world.  The menacing serpent that Rabbi Yochanan in Bava Kamma 117) saw was a snake with its tail in its mouth, known in the Gemara as an “Achnai”. This is an ancient symbol, called the Ouroboros, which seems to connote the eternal cycle of life: Likely this is symbolized by the tail in its mouth, and possibly also because a snake sheds its skin and goes through a rebirth of sorts. The first known archaeological representation of the Ouroboros, is on one of the shrines enclosing the sarcophagus of Tutankhamun (see https://en.wikipedia.org/wiki/Ouroboros ) 

The ancient tradition of this Ouroboros is also related to the Leviathan, which has connotations of a powerful force present at the time of creation which God subdued (see Yeshaiyahu chapter 27, Iyov chapter 40, Bava Basra 74b, and Rashi Bereishis 1:21 quoting a midrash.) The Zohar (Tikkunei Zohar 52:2) describes it as similar to a circular intestine in the body. Similarly, the word Akalason found in those same verses in Yeshaiyahu (27) could be translated as a twisted serpent.  Thus the Leviathan, the Akalason and the Ouroboros seem to be one in the same. 

The Babylonian epic of Baal also describes a primordial battle of Baal with a giant serpentine creature. Even if it became distorted with idolatrous imagery, the Ouroboros may have been part of a shared mystical tradition from many ancient sources, originally a Jewish tradition. See Rambam (Laws of Idolatry 1:1), where he characterizes the original idolaters as having descended from Adam’s progeny who worshiped God, but then distorted their teachings.  We also might wonder if King Tutankhamun utilized the Ouroboros-Leviathan symbol as part of a tradition learned from Joseph. The Midrash (Sotah 36b) tells us that Yosef taught Pharaoh Hebrew; perhaps he taught him a whole lot more. 

The evil inclination is an essential but twisted serpent. We need it because it represents our drives and the essence of physicality by which we cannot live. Like the skin of a snake it sheds itself and does not what it seems, like the Achnai it is circular and eats its own tail because but due to it, we cannot be fully connected to God, and are subject to entropy and death. Yet, we cannot live in this world without it. Nevertheless, like all bullies, the Yetzer Hara is both big and small, depending on your perspective, attitudes, fears and triggers.