They resemble all other pagan idols. It’s where the Catholic Church got them from.
This is the scripture reference:
God said to satan....
"And I will put enmity between you and the woman, and between your offspring and hers; he (Jesus) will crush your head, and you will strike his heel." Gen. 3:15
We as Christians, know that this verse points directly to the promise made of Christ, as the Deliverer of fallen man from 'the power' of Satan, through His death, and resurrection....(a fatal blow against satan).
So even today we have a 'generation of vipers' on the one hand, and the people who are God's people in Christ on the other.