Amphisbaena

A serpent with one head at each end of its body, able to move forward or backward equally well, or even bite one head with the other and roll like a wheel. Legend says it was born from Medusa's own blood, spilled in the desert when her severed head was carried across those sands.

A serpent whose Greek name means 'goes both ways': it has a head at each end and can move forward or backward, or bite one head onto the other and roll like a wheel. It is said to be born from the blood of beheaded Medusa, spilled in the Libyan desert.

Within the folk and mythological corpus compiled by the Codex Monstrorum, the creature Amphisbaena occupies a distinctive role in the symbolic imagination of its culture of origin. Its mythos articulates primal human anxieties, the mystery of untamed wilderness, and social norms preserved through the lens of bestiary literature.

A probable mythologization of real worm-lizards (amphisbaenians), whose blunt tail looks like a second head and which move both ways. The ancients ascribed it medicinal properties (its skin would cure rheumatism and aid woodcutters and pregnant women).

Used in ancient pharmacopeia and as an amulet; in the bestiaries its two heads symbolize duplicity and sin. The ability to go in two directions made it an emblem of ambivalence, contradiction, and watchfulness both ways.

First appearance and primary records: A two-headed serpent (one head at each end) of the Greco-Roman tradition, mentioned by Nicander, Lucan (Pharsalia, describing the serpents of Libya), and Pliny the Elder; it passed to the medieval bestiaries.

Oral transmissions and preserved manuscripts indicate that legends surrounding Amphisbaena underwent substantive evolution over successive centuries. From archaic oral traditions to classical and medieval written records, each period reframed the creature according to its own ethical and cosmological paradigms.

A serpent with a head at each end, eyes glowing like lanterns in some versions, sometimes given legs and ears in medieval iconography; it moves both ways and rolls in a circle.

It symbolizes duality, contradiction, and the impossibility of being surprised from behind (it watches both ways); in Christian morality it embodies the duplicity of sin. It binds wonder, ancient medicine, and the symbolism of ambivalence.

Like Medusa, the amphisbaena shares an origin in the Gorgon's blood and the serpent theme; it stands out for its two heads (a bicephalous motif found in many cultures) and the symbolism of bidirectionality.

From Lucan's Pharsalia to the bestiaries and heraldry, and onward to Borges (who gathered it in his bestiary) and pop culture, the amphisbaena is the archetypal two-headed serpent of the West.