"J.A. MacCulloch, in his book the Religion of the Ancient Celts, mentions the altar of Cernunnos at Paris and describes other ancient religious artifacts depicting the Horned God:
...On the altar of Beaune are three figures, one horned with a cornucopia, another three-headed, holding a basket...One god was three-faced, the other has a cornucopia which he offers to a serpent...another image represents a three-faced God, holding a serpent with a ram's head...Above a seated god and goddess on an altar from Malmaison is a block carved to represent three faces. To be compared with these are seven steles from Reims, each with a triple face by only one pair of eyes. Above some of these is a ram's head. On eight stele the heads are separated...They were all gods and goddesses of fertility and the underworld. MacCulloch writes 'Cernunnos may this have been regarded as a three-headed, horned, squatting god, with a torque and a ram's-headed serpent. But a horned god is sometimes a member of a triad, perhaps representing myths in which Cernunnos was associated with other gods. The three-headed god may be the same as the horned god, though on the Beaune altar they are distinct. The various representations are linked together, but it is not certain that all are varying types of one god. Horns, torque, horned snake, or even the triple head may have been symbols pertaining to more than one god, though generally associated with Cernunnos."
Witchcraft: The Old Religion
~Dr. Leo Louis Martello~