BONNACON, BONACONN
Mythology of Asia
These are variations on the name of a fabulous animal said to inhabit the desert and scrublands of Asia, that appears in ancient texts of Europe. The BONNACON, also called the BONACHUS and BONASUS, is described by PLINY THE ELDER in his "Historia Naturalis" (AD 77) as a bovine creature with the mane of a horse and enormous in-curving horns. (In later texts these are described as green.) This otherwise unremarkable creature possesses a defense mechanism that was more effective then it's horns: when pursued, it would defecate so voluminously that the drug was said to cover over two acres and be so acrid as to burn trees, grass, hunters, and dogs alike. The BESTIARIES of the eleventh and twelfth centuries depicts this event most graphically.
Source: Giants, Monsters, and Dragons: An Encyclopedia of Folklore, Legend, and Myth