The corn goddess and wife of Tegid Voel, mother of Taliesin in non-Arthurian Welsh legend. She is usually represented as a crone, the goddess of dark, prophetic powers, whose totem animal is the sow, which represents the fecundity of the Otherworld.
She was the mother of a hapless son, Taliesin, who was called Morfran, but nicknamed Afgaddu.
She was preparing a magic cauldron for him, three drops from which would reveal all secrets, past, present and future. When Gwion, the cauldron’s attendant, accidentally imbibed the drops, he was swallowed by Ceridwen when he was in the form of a grain of wheat and she in that of a hen. She then gave birth to him as Taliesin. This story seems far older than the period of the historical Taliesin.
It is similar to a tale told about the Irish hero, Finn mac Cool, and may enshrine a Celtic divinatory practice involving thumb chewing. This practice was known in early Ireland as Imbas Forosnai and seems to have rested on the notion that chewing the raw flesh of the thumb imparted sagacity.