Hebraic Beasts and Where to Find Them Part 2: The Ziz and the Bar Yochni
וְאָמַר רַבָּה בַּר בַּר חָנָה זִימְנָא חֲדָא הֲוָה אָזְלִינַן בִּסְפִינְתָּא וַחֲזֵינַן הָהוּא צִיפְּרָא דְּקָאֵים עַד קַרְצוּלֵיהּ בְּמַיָּא וְרֵישֵׁיהּ בִּרְקִיעַ וְאָמְרִינַן לֵיכָּא מַיָּא וּבָעֵינַן לֵחוּת לְאִקּוֹרֵי נַפְשִׁין וּנְפַק בַּת קָלָא וְאָמַר לַן לָא תֵּיחוּתוּ הָכָא דִּנְפַלַת לֵיהּ חֲצִיצָא לְבַר נַגָּרָא הָא שַׁב שְׁנֵי וְלָא קָא מָטְיָא אַאַרְעָא וְלָאו מִשּׁוּם דִּנְפִישִׁי מַיָּא אֶלָּא מִשּׁוּם דִּרְדִפִי מַיָּא אָמַר רַב אָשֵׁי וְהָהוּא זִיז שָׂדַי הוּא דִּכְתִיב וְזִיז שָׂדַי עִמָּדִי
And Rabba bar bar Ḥana said: Once we were traveling in a ship and we saw a certain bird that was standing with water up to its ankles [kartzuleih] and its head was in the sky. And we said to ourselves that there is no deep water here, and we wanted to go down to cool ourselves off. And a Divine Voice emerged and said to us: Do not go down here, as the ax of a carpenter fell into it seven years ago and it has still not reached the bottom. And this is not because the water is so large and deep. Rather, it is because the water is turbulent. Rav Ashi said: And that bird is called ziz sadai, wild beast, as it is written: “I know all the fowls of the mountains; and the ziz sadai is Mine” (Psalms 50:11).

R. Chiya taught in the name of R. Meir (from Job 12:7), “’But ask the beasts, and they will teach you; the birds of the sky, they will tell you’: ’But ask the beasts,’ this is the behemoth; ‘the birds of the sky,’ this is the ziz of the Omnipresent (a giant bird). [(Job 12:8) ‘Or speak to the earth, it will teach you; the fish of the sea, they will inform you’:] ‘Or speak to the earth,’ this is the Garden of Eden; ‘The fish of the sea,’ that is the leviathan. (Job 12:9) ‘Who among all these does not know that the hand of the Lord has done this?’”

(52) As leviathan is the king of fishes, so the ziz is appointed to rule over the birds. His name comes from the variety of tastes his flesh has; it tastes like this, zeh, and like that, zeh. The ziz is as monstrous of size as leviathan himself. His ankles rest on the earth, and his head reaches to the very sky.

(53) It once happened that travellers on a vessel noticed a bird. As he stood in the water, it merely covered his feet, and his head knocked against the sky. The onlookers thought the water could not have any depth at that point, and they prepared to take a bath there. A heavenly voice warned them: "Alight not here! Once a carpenter's axe slipped from his hand at this spot, and it took it seven years to touch bottom." The bird the travellers saw was none other than the ziz. His wings are so huge that unfurled they darken the sun. They protect the earth against the storms of the south; without their aid the earth would not be able to resist the winds blowing thence. Once an egg of the ziz fell to the ground and broke. The fluid from it flooded sixty cities, and the shock crushed three hundred cedars. Fortunately such accidents do not occur frequently. As a rule the bird lets her eggs slide gently into her nest. This one mishap was due to the fact that the egg was rotten, and the bird cast it away carelessly. The ziz has another name, Renanin, because he is the celestial singer. On account of his relation to the heavenly regions he is also called Sekwi, the seer, and, besides, he is called "son of the nest," because his fledgling birds break away from the shell without being hatched by the mother bird; they spring directly from the nest, as it were. Like leviathan, so ziz is a delicacy to be served to the pious at the end of time, to compensate them for the privations which abstaining from the unclean fowls imposed upon them.

(5) Nor is this world inhabited by man the first of things earthly created by God. He made several worlds before ours, but He destroyed them all, because He was pleased with none until He created ours. But even this last world would have had no permanence, if God had executed His original plan of ruling it according to the principle of strict justice. It was only when He saw that justice by itself would undermine the world that He associated mercy with justice, and made them to rule jointly. Thus, from the beginning of all things prevailed Divine goodness, without which nothing could have continued to exist. If not for it, the myriads of evil spirits had soon put an end to the generations of men. But the goodness of God has ordained, that in every Nisan, at the time of the spring equinox, the seraphim shall approach the world of spirits, and intimidate them so that they fear to do harm to men. Again, if God in His goodness had not given protection to the weak, the tame animals would have been extirpated long ago by the wild animals. In Tammuz, at the time of the summer solstice, when the strength of behemot is at its height, he roars so loud that all the animals hear it, and for a whole year they are affrighted and timid, and their acts become less ferocious than their nature is. Again, in Tishri, at the time of the autumnal equinox, the great bird ziz flaps his wings and utters his cry, so that the birds of prey, the eagles and the vultures, blench, and they fear to swoop down upon the others and annihilate them in their greed. And, again, were it not for the goodness of God, the vast number of big fish had quickly put an end to the little ones. But at the time of the winter solstice, in the month of Tebet, the sea grows restless, for then leviathan spouts up water, and the big fish become uneasy. They restrain their appetite, and the little ones escape their rapacity.

אמר הקב"ה בעולם זה אכלתם את המן בזכות אבותיכם, אבל לעולם הבא אני מאכיל אתכם בהמות זיז ולויתן, אתם אוכלים בזכות עצמיכם, שנאמר יכרו עליו הברים יחצוהו בין כנענים (איוב מ ל).

The Holy One said: In this world you have eaten manna through the merit of your ancestors; but in the world to come I will feed you cattle, <i.e.,> Ziz and Leviathan. You will eat through your own merit. Thus it is stated (concerning Leviathan in Job 40:30 [41:6]): SHALL TRADE ASSOCIATES MAKE A BANQUET OF HIM? SHALL THEY DIVIDE HIM UP AMONG MERCHANTS?

רַבִּי מְנַחֲמָא וְרַבִּי בֵּבַי וְרַבִּי אַחָא וְרַבִּי יוֹחָנָן בְּשֵׁם רַבִּי יוֹנָתָן אָמְרוּ תַּחַת מַה שֶּׁאָסַרְתִּי לְךָ הִתַּרְתִּי לָךְ, תַּחַת אִסּוּר דָּגִים לִוְיָתָן דָּג טָהוֹר, תַּחַת אִסּוּר עוֹפוֹת זִיז עוֹף טָהוֹר הוּא, הֲדָא הוּא דִכְתִיב (תהלים נ, יא): יָדַעְתִּי כָּל עוֹף הָרִים וְזִיז שָׂדַי עִמָּדִי. אָמַר רַבִּי יְהוּדָה בְּרַבִּי סִימוֹן בְּשָׁעָה שֶׁהוּא פּוֹרֵשׂ אֶת כְּנָפָיו מַכְּהֶה גַּלְגַּל חַמָּה, הֲדָא הוּא דִכְתִיב (איוב לט, כו): הֲמִבִּינָתְךָ יַאֲבֶר נֵץ יִפְרֹשׂ כְּנָפָו לְתֵימָן, וְלָמָּה נִקְרָא שְׁמוֹ זִיז, שֶׁיֵּשׁ בּוֹ כַּמָּה מִינֵי טַעַם מִזֶּה וּמִזֶּה.

אָמַר רַבִּי מֵאִיר (איוב יב, ז): וְאוּלָם שְׁאַל נָא בְהֵמוֹת וְתֹרֶךָּ, זֶה בְּהֵמוֹת, (איוב יב, ז): וְעוֹף הַשָּׁמַיִם וְיַגֶּד לָךְ, זֶה זִיז שָׂדָי, (איוב יב, ח): אוֹ שִׂיחַ לָאָרֶץ וְתֹרֶךָּ, זֶה גַּן עֵדֶן, (איוב יב, ח): וִיסַפְּרוּ לְךָ דְּגֵי הַיָּם, זֶה לִוְיָתָן, (איוב יב, ט): מִי לֹא יָדַע בְּכָל אֵלֶּה כִּי יַד יקוק עָשְׂתָה זֹאת.

פעם אחת נפלה ביצת בר יוכני וטבעה ששים כרכים ושברה שלש מאות ארזים ומי שדיא ליה והא כתיב (איוב לט, יג) כנף רננים נעלסה אמר רב אשי ההוא מוזרתא הואי:
Rabbi Yishmael ben Satriel also testified before Rabbi Yehuda HaNasi: Once an egg of the bird called bar yokhani fell, and the contents of the egg drowned sixty cities and broke three hundred cedar trees. The Gemara asks: And does the bar yokhani bird throw its eggs to the ground? But isn’t it written: “The kenaf renanim bird rejoices, but are her wings and feathers those of the stork? For she leaves her eggs on the earth, and warms them in dust” (Job 39:13–14)? The Sages understood that kenaf renanim is another name for the bar yokhani bird. If so, how could its egg fall if it lays its eggs on the ground? Rav Ashi said in explanation: That egg was unfertilized, and since it would never hatch the bird threw it to the ground.