Rabbah said: I myself saw a one-day-old wild ox, and it was as big as Mount Tabor. And how big is Mount Tabor? Four parasangs. And the length of its neck was three parasangs, and the resting place of its head was a parasang and a half. It cast forth a ball of dung, and it dammed up the Jordan.
The Re'em
Bava Batra 73a
אָמַר רַבָּה: לְדִידִי חֲזֵי לִי אוּרְזִילָא בַּר יוֹמֵיהּ, דַּהֲוָה כְּהַר תָּבוֹר. וְהַר תָּבוֹר כַּמָּה הָוֵי? אַרְבַּע פַּרְסֵי. וּמְשָׁאכָא דְצַוְּארֵיהּ תְּלָתָא פַּרְסֵי, וּבֵי מַרְבַּעְתָּא דְרֵישֵׁיהּ פַּרְסָא וּפַלְגָא. רְמָא כּוּפְתָּא, וּסְכַר לֵיהּ לְיַרְדְּנָא.