The Ouroboros — the serpent devouring its own tail — occupies a position of singular structural importance across the depth-psychology corpus. It functions simultaneously as cosmogonic image, psychological archetype, and alchemical emblem of circulatio. Neumann provides the most sustained mythological foundation, reading the Ouroboros as the primal symbol of pre-egoic containment: hermaphroditic, self-begetting, and representing the pleroma of undifferentiated unconscious existence before the hero’s separating consciousness can emerge. Jung, writing across Aion, Mysterium Coniunctionis, and The Structure and Dynamics of the Psyche, treats the symbol as both cosmological cipher — identifying it with Aion, eternity, and the opus circulatorium of alchemy — and as an analogue for the individuation process itself, in which the prima materia that begins the opus also constitutes its telos. Von Franz extends this alchemical reading, demonstrating how the Ouroboros and its variants (the pelican, the two-bird motif, the battling winged and wingless serpents) articulate the circulatory logic of psychic transformation. Hillman inflects the symbol through his pellucid reading of the pelican as a sophistication of the Ouroboros, emphasizing iteratio and sacrificial repetition over triumphant synthesis. Abraham situates the figure squarely within the opus alchymicum as the symbol of its circular, self-consuming process. The key tension in the corpus lies between the Ouroboros as image of original wholeness — a state the ego must overcome — and as goal-state achieved through completed individuation, wherein the beginning and end are revealed as identical.