*naḥaš- - snake (SED II No. 159, Kogan 2015: 300)

may go back to the verbal root *nḥš‘to live, to be alive’ preserved in Akk.nêšu. For semantic development see Buck 1949:137 (numerous IE precedents) and, in the Semitic domain, Hbr. ḥayyā‘animaľ