At the end of days, God will host a banquet for the righteous, and the main course will be the Leviathan. According to Bava Batra 74b, this is not metaphor. The Sages described the preparation in concrete detail.
Rav Yehuda said in the name of Rav: everything God created, He created male and female—including the Leviathan. There was originally a male and a female sea monster. But God realized that if they reproduced, the world could not survive. So He killed the female and salted her flesh, preserving it for the feast of the righteous in the World to Come.
The male Leviathan lives on. When it is hungry, its breath boils all the waters of the deep (Job 41:23). If it did not keep its head in the Garden of Eden, no creature could withstand its smell. When it is thirsty, it makes furrows in the sea—and the water level does not return to normal for seventy years.
Gabriel is assigned to hunt the Leviathan. But even Gabriel cannot do it alone—only God Himself can wield the sword that approaches the creature (Job 40:19).
Rabba taught, citing Rabbi Yohanan: in the future, God will prepare a feast from the Leviathan's flesh for the righteous. The proof text: "The companions hearken for your voice" (Song of Songs 8:13)—the "companions" are Torah scholars. Whatever meat remains will be sold in the markets of Jerusalem, because "they will part him among the merchants" (Job 40:30).
From the Leviathan's skin, God will build a sukkah (סוכה) for the most deserving righteous. For those slightly less worthy, a head covering. For those below that, a necklace. For the least deserving, an amulet. The remainder of the skin will be draped over the walls of Jerusalem, and its radiance will illuminate the entire world.