It seems that Yig, the snake-god of the central plains tribes—presumably the primal source of the more southerly Quetzalcoatl or Kukulcan—was an odd, half-anthropomorphic devil of highly arbitrary and capricious nature. He was not wholly evil, and was usually quite well disposed toward those who gave proper respect to him and his children, the serpents; but in the autumn he became abnormally ravenous and had to be driven away by means of suitable rites. That was why the tom-toms in the Pawnee, Wichita, and Caddo country pounded ceaselessly week in and week out in August, September, and October; and why the medicine-men made strange noises with rattles and whistles curiously like those of the Aztecs and Mayas.