Symbols of monotheistic religion?

We all know that the "official" symbols of the three monotheistic religions are: Christianity-Cross, Islam-Crescent Moon, Hebraism-Maghen (David's shield). But recently I came across a booklet that used animals to identify the three religions: Christianity-Lion, Islam-Hawk, Hebraism-Snake... the booklet was mainly written in Hebrew, so I couldn't understand it very well, apart from the fact that it dealt with peace among the three religions. Can somebody help? Thanks!