Genesis 3:14-15

14 Then the Lord God said to the serpent,

“Because you have done this, you are cursed
    more than all animals, domestic and wild.
You will crawl on your belly,
    groveling in the dust as long as you live.
15 And I will cause hostility between you and the woman,
    and between your offspring and her offspring.
He will strike your head,
    and you will strike his heel.”