The Jaguar
Even the Olmec 'were-jaguar' is disputed: in 1981 Carson Murdy argued that most of its features match infants with neural tube defects rather than a jaguar.
Carson N. Murdy, 'Congenital Deformities and the Olmec Were-Jaguar Motif', American Antiquity 46, no. 4 (1981), 861–871
The jaguar in the art, myth and shamanism of the Americas, from Olmec sculpture to Amazonian trance.