Ouroboros

Ouroboros is an ancient symbol depicting a serpent or dragon devouring its own tail, forming a circle. The name comes from Greek ouroboros, from ouros meaning tail and boros meaning devourer. The image is associated with cyclicality, continuity, and the eternal return.

Throughout antiquity the ouroboros appears in multiple traditions. In ancient Egypt it is linked with renewal and the endless cycle of life, death, and rebirth; it appears in temple art and later magical texts. In Greco-Roman, Hermetic, and Gnostic writings the symbol is used to express unity of opposites and the self-sustaining nature of the cosmos. In alchemy it embodies the reconciliation of spirit and matter and the perpetual transformation from one state to another, sometimes encircling other symbols within a circle.

Interpretations: In psychology, Carl Jung popularized the idea of the ouroboros as a symbol of wholeness and the process of individuation, the integration of opposing aspects of the psyche.

Modern usage: The symbol continues in art, literature, and popular culture as a sign of continuity, cyclic processes, or self-renewal. It has been adopted in branding and insignia, and in contemporary science and technology contexts; notably, Ouroboros is the name of a proof-of-stake consensus protocol used by the Cardano blockchain.