Monkey Hide

Protector of Horses, Protector of the Stables
Quivers Covered in Monkey Hide

Monkey Riding Horse Japanese Netsuke Courtesy rubylane.com Monkey Riding Horse (ichibanantiques.com)

In Chinese and Japanese artwork, the monkey is often shown riding the horse. This symbolism too stems from the classic Chinese story (see above) called Journey to the West, in which the Jade Emperor appoints the Monkey to the post of “Protector of Horses” to pacify the monkey’s desire for power and recognition. See parts of this story here (by Aaron Shepard, outside link). The monkey soon discovers that his posting as Stable Protector is empty (without real power or merit), and again returns to his mischievous ways, causing trouble for all until he is defeated by the Buddha.

Elsewhere, in the Japanese Saru no Soshi 猿の草子 (Scroll of the Monkey), an entertaining illustrated scroll from the late 16th century (see photo below) describing the marriage of the daughter of the monkey head-priest of Hiyoshi Shrine to a monkey from Yokawa, we find two monkey attendants discussing the proper way to carry a quiver. In those bygone days, Japanese quivers actually had covers made of monkey hide. This monkey-hide covering was believed to protect the warrior’s horse against illness and injuries. <Source: Author Takeuchi Lone, from the Japanese Journal of Religious Studies, 1996, 23/1-2> 

Saru no Soshi (Scroll of the Monkey)
Late 16th Century, One Section of the Japanese Scroll
 Photo courtesy of British Museum, where the scroll is kept.

Stable Protector
Toshogu Shrine, Nikko, Japan A famous carving of the three monkeys is found at the 17th-century Toshogu Shrine, a complex built to honor Tokugawa Ieyasu, the founder of the Tokugawa Shogunate (1603-1868 AD). The carving is located on the eaves of the Shinkyusha (Sacred Stable), again reflecting the monkey’s role as protector of the stables, a role that originated in the Chinese novel Journey to the West. Eight panels are carved on the wall of the shrine’s horse stable. The panel shown above depicts the three monkeys "hear no evil, speak no evil, and see no evil."

Sarumimi 猿耳 -- Literally “Monkey Ears”
The origin of the term Sarumimi is unclear, but it may be related to the custom, already established in the Kamakura era, of keeping pet monkeys in the vicinity of stables, apparently to protect the horses from sickness and ill-fortune. <quoted from JAANUS>  

12 Zodiac Animals Associated with Eight Buddhist Deities
Exact dates are hard to determine, but it was probably in Japan’s Edo Period (1603 - 1867 AD) that the Japanese began associating each of the 12 Chinese zodiac animals with one specific Buddhist patron deity, the Eight Buddhist Protector Deities. For reasons unknown to me, there are only eight patron Buddhist deities, not 12.