In Jewish religious texts, the first mention of a dragon-like creature is in the Biblical works of Job (26:13), and Isaiah (27:1) where it is called Nachash Bare'ach, or a "Pole Serpent".^[11] This is identified in the Midrash Rabba to Genesis 1:21 as Leviathan from the word Taninim (תנינים) "and God created the great sea-monsters."^[12] In modern Hebrew the word Taninim is used for Crocodiles - however, this is a 20th Century usage unconnected with the original Biblical meaning.^{[citation needed]}

In Jewish astronomy this is also identified with the North Pole, the star Thuban which, around 4,500 years ago, was the star in the Draco constellation's "tail".^[11] However this can also have been either the celestial pole or the ecliptic pole. The ancient observers noted that Draco was at the top of the celestial pole, giving the appearance that stars were "hanging" from it, and in Hebrew it is referred to as Teli, from talah (תלה) - to hang.^[13] Hebrew writers from Arabic-speaking locations identified the Teli as Al Jaz'har, which is a Persian word for a "knot" or a "node" because of the intersection of the inclination of the orbit of a planet from the elliptic that forms two such nodes. In modern astronomy these are called the ascending node and the descending node, but in medieval astronomy they were referred to as "dragon's head" and "dragon's tail".^[14]