Later Jewish sources describe Leviathan as a dragon who lives over the sources of the Deep and who, along with the male land-monster Behemoth, will be served up to the righteous at the end of time.
This creature was like a bad creature to the Jewish back then and whenever they would see them would mean it was the end of time and that god made fewer of them so nothing bad would happen. (https://www.pinterest.com/pin/56506170321636535/)