Yanwei

The final chapter records a god with a human head on a serpent's body, long as a chariot shaft, with a head at either end, dressed in purple robes and a red felt cap: Yanwei. The text appends a startling promise — a ruler of men who obtains it and feasts it will become hegemon of all under heaven.

Guo Pu's commentary identifies it at a stroke with the Weiyi of the Zhuangzi. There, Duke Huan of Qi goes hunting in the marshes, sees a ghost, and takes to his bed. The gentleman Huangzi Gao'ao tells him what lives in marshes: a creature called Weiyi, thick as a wheel-hub and long as a chariot shaft, in purple robes and a scarlet cap, which so hates the sound of thunder-carts that it clasps its head and rises when it hears them — 'he who sees it is close to hegemony.' The duke's gloom breaks; he laughs, 'That is exactly what I saw!', straightens his robes to sit talking with his guest, and before the day is out the illness is gone without his noticing. An anxiety cured by a favorable identification.

In his Fuxi Kao, Wen Yiduo advanced a famous reading: Yanwei or Weiyi — one serpent body with a human head at each end — preserves the image of the intertwined creator pair, exactly as Han dynasty silk paintings and carved stones show Fuxi and Nüwa with human heads and coiled serpent tails. On this view the marsh god is a creation idol worn down into a country omen; the argument remains unavoidable in any discussion of Yanwei.