"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."
H.P. Lovecraft & Zealia Bishop, The Curse Of Yig
"Another reptilian deity, the feathered serpent Kukulcan, may be but another aspect of Itzamna."
"One such scene portrays a human sacrifice to Kukulcan, the feathered serpent, patron deity of the center."
Robert Sharere & Loa Traxler, The Ancient Maya
"Kukulcan is said to have come to Chichen Itzá, depictions of a masked individual backed by a feathered serpent may refer to the actual historical individual. However the historical figure may have been apotheozised at death as his namesake, thus further blurring the distinction between the man an the god."
Mary Miller & Karl Taube, The Gods and Symbols Of Ancient Mexico and the Maya