Within the depth-psychological corpus, the Serpent emerges as one of the most semantically overdetermined symbols in the entire lexicon — simultaneously chthonic daemon and divine wisdom-bearer, instrument of deception and agent of transformation, emblem of instinct and figure of transcendence. Jung’s treatment is the gravitational centre: in *Aion*, *Psychology and Alchemy*, *The Red Book*, and the seminar literature, he insists on the serpent’s inner polarity, its simultaneous alignment with Christ and devil, shadow and wisdom, the unconscious and the Self. The Gnostic Naassene tradition, which identifies the serpent with the world-soul inhabiting all things, becomes for Jung a mythopoetic language for the Mercurius-archetype. Campbell extends the symbol cross-culturally, tracing the serpent’s role as master of rebirth — through skin-shedding and lunar analogy — across Sumerian, Hindu, Ophite Christian, and Mesoamerican traditions. Hoeller maps the serpent onto the Jungian individuation schema by way of the Kundalini and the Gnostic Anthropos. Zimmer anchors the symbol in Indian iconography and the nāga complex. Across these voices, the central tension is irreducible: the serpent is never safely domesticated into either a merely negative or a merely redemptive valence. Its defining characteristic, for depth psychology, is precisely this polarity — the capacity to poison or to deify.