Samael and Lilith
They were the evil counterparts of Adam and Eve. Kind of like their antithesis.
In Jewish legend, Lilith was the first female God created out of the mud, equal to Adam. On their first night of existence, they discovered sexual intercourse, just like every other being created. Adam wanted to be on top of Lilith but she refused indignantly, claiming she is not inferior to man and would not bow before him just because he was created first. Adam was infuraited with Lilith. She fled from the Garden of Eden into the shores of the Red Sea, all while throwing him curses.
God sent 3 archangels after Lilith. He ordered that she return back to Eden, else be thrown into the sea. One of the archangels, Samael, was filled with lust for Lilith. Instead of fulfilling what God has tasked him to do, he killed the two others and wooed Lilith, saying she doesn’t have to bow down to anyone anymore if she chose him over God.
Together, their union created all known demons. It is said that Lilith gives birth to a thousand babies everyday, each in search for the descendants of Adam, whom Lilith still bore a grudge with.