Oedipus becomes a hero and dragon slayer because he vanquishes the Sphinx. This Sphinx is the age-old foe, the dragon of the abyss, representing the might of the Earth Mother in her uroboric aspect.
Neumann argues that the Sphinx embodies the uroboric Earth Mother’s fatal power, and that Oedipus’s conquest of her is identical with heroic incest — both being expressions of the ego’s differentiation from the Great Mother.
, The Origins and History of Consciousness (Princeton, 2019thesis