Last updated: 05-17-2025

Sun Wukong faces his evil double, the Six-Eared Macaque, in chapters 56 to 58 of Journey to the West (Xiyouji, 西遊記, 1592, “JTTW” hereafter). After the twin Mind Monkeys battle their way to the Western Paradise, the Buddha reveals the doppelganger’s true identity, noting that he and Monkey are two of four celestial primates (sihou hunshi, 四猴混世, lit: “four monkeys of havoc”) with amazing abilities:

“The first,” said Tathagata, “is the Stone-Monkey of Numinous Wisdom [Lingming shihou, 靈明石猴], [1] who

Knows transformations,
Recognizes the seasons,
Discerns the advantages of earth,
And is able to alter the course of planets and stars.

The second is the Red-Buttocked Horse-Monkey [Chikao mahou, 赤尻馬猴], who

Has knowledge of yin and yang,
Understands human affairs,
Is adept in its daily life
And able to avoid death and lengthen its life.

The third is the Long-Armed Gibbon [Tongbi yuanhou, 通臂猿猴], who can

Seize the sun and the moon,
Shorten a thousand mountains,
Distinguish the auspicious from the inauspicious,
And manipulate planets and stars.

The fourth is the Six-Eared Macaque [Liu’er mihou, 六耳獼猴] who has

A sensitive ear,
Discernment of fundamental principles,
Knowledge of past and future,
And comprehension of all things.

These four kinds of monkeys are not classified in the ten categories [of life], nor are they contained in the names between Heaven and Earth. As I see the matter, that specious Wukong must be a six-eared macaque, for even if this monkey stands in one place, he can possess the knowledge of events a thousand miles away and whatever a man may say in that distance” (based on Wu & Yu, 2012, vol. 3, p. 115).

如來道：「第一是靈明石猴，通變化，識天時，知地利，移星換斗；第二是赤尻馬猴，曉陰陽，會人事，善出入，避死延生；第三是通臂猿猴，拿日月，縮千山，辨休咎，乾坤摩弄；第四是六耳獼猴，善聆音，能察理，知前後，萬物皆明。此四猴者，不入十類之種，不達兩間之名。我觀假悟空乃六耳獼猴也。此猴若立一處，能知千里外之事；凡人說話，亦能知之。

In this article, I would like to explore all mentions of these magical creatures in the novel. I will focus more on the second and third primates as I’ve already written extensively about the first and fourth kind.

Table of Contents

• 1. Stone-Monkey
• 2. Horse-Monkey and Gibbon
  • 2.1. True Identity?
• 3. Six-Eared Macaque
• 4. The Same or Similar?
• 5. Updates

1. Stone-Monkey

There isn’t much to write about the “Stone-Monkey of Numinous Wisdom” (Lingming shihou, 靈明石猴) (fig. 1) as it’s clearly Sun Wukong. The term lingming (靈明) can also be translated as “Numinous Luminosity.” Both refer to spiritual wisdom. This explains why Sun Wukong attains so much power after only three years of spiritual cultivation.

Fig. 1 – A poster of the Stone-Monkey of Numinous Wisdom from the film Four Monkeys. The name has since been changed. See the 02-20-22 update below.

2. Horse-Monkey and Gibbon

I’m grouping these two together because they share a close association in JTTW. The Chinese term for “Red-Buttocked Horse-Monkey” (Chikao mahou, 赤尻馬猴) (fig. 2) appears three times in the novel, while “Horse-Monkey” (馬猴, Mahou) only appears once (see here). [2] The term “(Arms)-Through-the-Back Gibbon” (Tongbei yuanhou, 通背猿猴) appears three times, while the interchangeable term “Connected Arms Gibbon” (Tongbi yuanhou, 通臂猿猴) appears once (see here and here) (fig. 3). Both essentially mean “Long-Armed Gibbon.” (This refers to the belief that the small ape’s long, agile arms were somehow connected (i.e. tongbi, 通臂), passing through the back (i.e. tongbei, 通背) (Gulik, 1967, p. 92-93).) The term “ape” or “gibbon” (yuanhou, 猿猴) appears 16 times (see here), and it’s even used to refer to Monkey. For example, a poem in chapter seven calls him “The Great Sage, Equal to Heaven, a monstrous ape” (Qitian dasheng yuanhou guai, 齊天大聖猿猴怪) (Wu & Yu, 2012, vol. 1, p. 191). Horse-monkeys and gibbons are surprisingly listed among the Monkey King’s retinue:

The Handsome Monkey King thus led a flock of gibbons [猿猴], macaques [mihou, 獼猴], and horse-monkeys [馬猴], some of whom were appointed by him as his officers and ministers (based Wu & Yu, 2012, vol. 1, p. 106).

美猴王領一群猿猴、獼猴、馬猴等，分派了君臣佐使。

It’s actually a long-armed gibbon who reveals the truth of spiritual beings escaping the hand of death, setting Monkey on his quest for immortality:

From among the ranks a long-armed gibbon [tongbei yuanhou, 通背猿猴] suddenly leaped forth and cried aloud, “If the Great King is so farsighted, it may well indicate the sprouting of his religious inclination. There are, among the five major divisions of all living creatures, only three species that are not subject to Yama, King of the Underworld.” The Monkey King said, “Do you know who they are?” The monkey said, “They are the Buddhas, the immortals, and the holy sages; these three alone can avoid the Wheel of Transmigration as well as the process of birth and destruction, and live as long as Heaven and Earth, the mountains and the streams.” “Where do they live?” asked the Monkey King. The monkey said, “They do not live beyond the world of the Jambudvipa, for they dwell within ancient caves on immortal mountains.” When the Monkey King heard this, he was filled with delight, saying, “Tomorrow I shall take leave of you all and go down the mountain. Even if I have to wander with the clouds to the comers of the sea or journey to the distant edges of Heaven, I intend to find these three kinds of people. I will learn from them how to be young forever and escape the calamity inflicted by King Yama” (based on Wu & Yu, 2012, vol. 1, p. 131).

只見那班部中，忽跳出一個通背猿猴，厲聲高叫道：「大王若是這般遠慮，真所謂道心開發也。如今五蟲之內，惟有三等名色不伏閻王老子所管。」猴王道：「你知那三等人？」猿猴道：「乃是佛與仙與神聖三者，躲過輪迴，不生不滅，與天地山川齊壽。」猴王道：「此三者居於何所？」猿猴道：「他只在閻浮世界之中，古洞仙山之內。」猴王聞之，滿心歡喜道：「我明日就辭汝等下山，雲遊海角，遠涉天涯，務必訪此三者，學一個不老長生，常躲過閻君之難。」

Apart from this, chapter two casts both the long-armed gibbons and red-buttocked horse-monkeys as knowledgeable elders:

As they were speaking, four older monkeys came forward, two horse-monkeys with red buttocks [chikao mahou, 赤尻馬猴] and long-armed gibbons [tongbei yuanhou, 通背猿猴]. Coming to the front, they said, “Great King, to be furnished with sharp-edged weapons is a very simple matter:’ “How is it simple?” asked Wukong. The four monkeys replied, “East of our mountain, across two hundred miles of water, is the boundary of the Aolai Country. In that country there is a king who has numberless men and soldiers in his city, and there are bound to be all kinds of gold, silver, copper, and iron works there. If the great king goes there, he can either buy weapons or have them made (based on Wu & Yu, 2012, vol. 1, p. 131).

正說間，轉上四個老猴，兩個是赤尻馬猴，兩個是通背猿猴，走在面前道：「大王，若要治鋒利器械，甚是容易。」悟空道：「怎見容易？」四猴道：「我們這山向東去，有二百里水面，那廂乃傲來國界。那國界中有一王位，滿城中軍民無數，必有金銀銅鐵等匠作。大王若去那裡，或買或造些兵器 。

Later in the chapter, they are appointed officers:

The Monkey King made the four old monkeys mighty commanders of his troops by appointing the two horse-monkeys with red buttocks [赤尻馬猴] as Marshals Ma [馬] and Liu [流], and the two long-armed gibbons as Generals Beng [崩] and Ba [芭] (based on Wu & Yu, 2012, vol. 1, p. 138).

猴王將那四個老猴封為健將，將兩個赤尻馬猴喚做馬、流二元帥，兩個通背猿猴喚做崩、芭二將軍。

These primates are mentioned in a few other chapters (see here and here).

Fig. 2 & 3 – “Four Monkeys” posters of the Red-Buttocked Horse-Monkey and the Long-Armed Gibbon.

2.1. True Identity?

Anthony C. Yu (Wu & Yu, 2012) calls the horse-monkey a “baboon” (vol. 3, p. 115, for example), likely based on the common image of the primate having a red bottom. And while searching “馬猴” does pull up images and articles about the Mandrill, a large, colorful cousin of the baboon (example), I can’t find any reliable historical sources linking the animal with the term. Having said that, this book associates it with the ancient Chinese practice of putting monkeys in horse stables (majiu husun, 馬廄猢猻) to ward off equine sicknesses, making it a “horse’s monkey.” This naturally has connections to Sun Wukong’s time as the Bimawen, or keeper of the heavenly horses. This is the most convincing explanation for the horse-monkey that I’ve seen, but I’ll make sure to update the article if any other plausible reasons arise. As for the red bottom, this is likely the sexual swelling of females. I’ll spare you a picture; just imagine a bright pink pumpkin that’s about to explode.

The gibbon and macaque are real world animals. For more information on Chinese views of the gibbon, please see this archived book.

3. Six-Eared Macaque

The Chinese term for macaque, mihou (獼猴), appears a total of 13 times (see here). Two refer to monkeys in general (here and here), while three refer to the Macaque King (Mihou wang, 獼猴王) (see here), Wukong’s sworn brother. A total of eight refer to the Six-Eared Macaque (Liu’er mihou, 六耳獼猴) (see here, here, and here).

I’ve already written an article exploring the literary and religious origins of Six Ears. The novel presents him as a negative manifestation of Sun Wukong’s mind. I suggest that their battle is an allegory for the internal struggle between the true and illusionary aspects of Monkey’s psyche. Another scholar has also posited that Six Ears appears earlier in the novel as the Macaque King.

Fig. 4 – A “Four Monkeys” poster of the Six-Eared Macaque. This version wields swords unlike his staff-brandishing literary counterpart.

4. The Same or Similar?

Let’s compare the Four Celestial Primates with the apes and monkeys from the Great Sage’s mountain home:

Four Celestial Primates

1. Stone-Monkey of Numinous Wisdom (Lingming shihou, 靈明石猴; i.e. Sun Wukong)
2. Red-Buttocked Horse-Monkey (Chikao mahou, 赤尻馬猴)
3. Long-Armed Gibbon (Tongbi yuanhou, 通臂猿猴)
4. Six-Eared Macaque (Liu’er mihou, 六耳獼猴). 

Flower-Fruit Mountain

1. Stone-Monkey (Shihou, 石猴; i.e. Sun Wukong)
2. Red-Buttocked Horse-Monkeys (Chikao mahou, 赤尻馬猴)
3. Long-Armed Gibbons (Tongbei yuanhou, 通背猿猴)
4. Macaques (Mihou, 獼猴)

Recall how the names Tongbi and Tongbei both refer to the gibbon’s long arms. Therefore, the listed groups above are practically the same.

This then raises the question: Were the Four Celestial Primates all born on Flower-Fruit Mountain, or are the similarities just an example of mirroring? What I mean by this is that JTTW hosts a number of mirrored characters. Here are just a few:

1. Sun Wukong and Six-Ears (ch. 56 to 58) – This one is obvious.
2. Sun Wukong and the Bull Demon King (ch. 4 to 7 and 61) – They have the same powers and character arc (see section 3 here).
3. The Demon Kings of the 72 Caves and the 72 Heavenly Commanders (ch. 4 to 5)
4. Monkey’s Six Sworn Demon King Brothers (ch. 4) and Lord Erlang’s Six Sworn Brothers of Plum Mountain (ch. 6)
5. Nezha and Red Boy (chapters 4 to 6 and 40 to 42) – Both are powerful, divine children associated with fire.

I’ll leave it up to the reader which possibility they want to accept.

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5. Updates

Update: 02-20-22

Here’s a four minute preview for the upcoming film King of Havoc: Rise of the Great Sage (Hunshi zhi wang: Dasheng jueqi,  混世之王：大圣崛起, 2022). The Six-Eared Macaque appears in figure four wielding swords. This same character takes part in the trailer but is called the Macaque King, thereby referencing the aforementioned theory that he is Six Ears.

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Update: 02-22-22

User Phantom86d left an interesting comment suggesting that the four celestial primates are not part of the ten categories of life—as stated by the Buddha in the introduction—”[b]ecause Wukong erased their names from the book of Life and Death.” This refers to chapter three when Sun inks out his name and those of all other primates when his immortal soul is mistakenly summoned to hell. It’s important to remember that he had his own, separate book (Wu & Yu, 2012, vol. 1, p. 140), so the other celestial primates likely had theirs.

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Update: 02-25-22

Thanks to this dictionary, I learned that one late-Qing source, New Dialect (Xinfangyan, 新方言, early-20th-c.), associates “horse-monkey” (mahou, 馬猴) with various iterations of Chinese terms for macaque monkeys:

“Bathing-monkey” (muhou): “mother-monkey” (muhou); mother-monkey (muhou): “full-monkey” (mihou) – these are called “horse-monkey” (mahou), the sound of each one changing [in turn].

沐猴：母猴；母猴：彌[獼]猴，令人謂之馬猴，皆一音之轉。(the original doesn’t have punctuation)

This article explains that the second term refers not to a female primate but a macaque. The Annotation of the Shuowen jiezi (Shuowen jiezi zhu, 說文解字注, 1815) reads:

“Mother-monkey” (muhou) is the name of the beast, not the female. “Bathing-monkey” (muhou) and “hunting-monkey” (mihou) are changes in dialect. The characters are wrong.

母猴乃此獸名，非謂牝者。沐猴、獮[獼]猴皆語之轉，字之訛也。

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Update: 02-26-22

The Compendium of Materia Medica (Bencao gangmu, 本草綱目, 1596) traces the etymology of “bathing monkey” (muhou, 沐猴):

The monkey likes to wipe its face as if bathing (mu), so it is called a “bathing (monkey).” Later generations mistook this mu for “mother,” and then mother for “full” (mi). The meaning is lost as errors compound.

猴好拭面如沐，故謂之沐，而後人訥沐為母，又謳母為獼，愈訥愈失矣。

It then directly connects muhou (母猴) to stable monkeys:

The Shuowen says: The characters (for macaque) look like “mother monkey” (muhou), but it’s a “bathing monkey” (muhou, i.e. macaque), not a female. Since a macaque resembles a hu-barbarian, he is also called hu-sun “grandson of a barbarian.” The Zhuangzi calls him ju. People who raise horses keep a macaque in the stables, which will ward off horse-diseases. The Hu barbarians call a macaque ma–liu, in Sanskrit books he is called Mo–si–zha (makaṭa).

《說文》雲︰為字象母猴之形。即沐猴也，非牝也。猴形似胡人，故曰胡孫。 《莊子》謂之狙。養馬者厩中畜之，能闢馬病，胡俗稱馬留雲。 《梵書》謂之摩斯[吒]。

The section later explains how macaques (muhou, 母猴) help the horses:

The Classic of Horses states: Domesticated macaques (muhou) used in horse stables help avoid horse diseases [lit: bimawen]. Their monthly menstruation runs onto the grass, and once the horses eat it, they will never be sick.

《馬經》言︰馬厩畜母猴，闢馬瘟疫。逐月有天癸流草上，馬食之，永無疾病矣。

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Update: 06-28-2023

It just occurred to me that since Six Ears is an aspect of Sun Wukong’s mind, the other two celestial primates could be as well. All three being aspects of Sun’s mind would thus explain why they “are not classified in the ten categories [of life], nor are they contained in the names between Heaven and Earth” (Wu & Yu, 2012, vol. 3, p. 115). They aren’t classified because they were never born. They are simply personifications of Sun’s base and noble qualities. How and when they would have splintered from his psyche is the big question. 

I doubt I’m the first person to think of this. I’m interested to hear what my readers think.

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Update: 01-04-24

I’ve rewritten sections two to four. This was done to help make the subject more understandable. 

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Update: 05-17-25

I was looking for something and happened upon a lovely drawing of the four celestial primates (fig. 5). It’s interesting that most of them are wielding staves. Though, only Monkey and the Six-Eared Macaque are associated with the weapon in JTTW.

Fig. 5 – The drawing (larger version). Image found here.

Notes:

1) I will be altering Yu’s (Wu & Yu, 2012) translation from this point forward to make it more accurate.

2) Ctext shows the term “Great Horse-Monkey” (Da mahou, 大馬猴) pops up in chapter 28 of Dream of the Red Chamber (18th-century). It’s used to symbolize something worse than an immoral husband that would ravage a young maiden:

Next came Xue Pan. “Is it for me to speak now?” Xue Pan asked.

“A maiden is sad…”

But a long time elapsed after these words were uttered and yet nothing further was heard.

“Sad for what?” Feng Ziying laughingly asked.

“Go on and tell us at once!”

Xue Pan was much perplexed. His eyes rolled about like a bell.

“A girl is sad…” he hastily repeated. But here again he coughed twice before he proceeded.

“A girl is sad,” he said:

“When she marries a spouse who is a libertine.”

This sentence so tickled the fancy of the company that they burst out into a loud fit of laughter.

“What amuses you so?” shouted Xue Pan, “is it likely that what I say is not correct? If a girl marries a man, who chooses to forget all virtue, how can she not feel sore at heart?”

But so heartily did they all laugh that their bodies were bent in two.

“What you say is quite right,” they eagerly replied. “So proceed at once with the rest.”

Xue Pan thereupon stared with vacant gaze.

“A girl is grieved…” he added.

But after these few words he once more could find nothing to say.

“What is she grieved about?” they asked.

“When a huge horse monkey [大馬猴] finds its way into the inner room,” Xue Pan retorted (Cao & Joly, 1892, p. 62).

下該薛蟠。薛蟠道：「我可要說了：女兒悲－－」說了半日，不見說底下的。馮紫英笑道：「悲什麼？快說！」薛蟠登時急的眼睛鈴鐺一般，便說道：「女兒悲－－」又咳嗽了兩聲，方說道：「女兒悲，嫁了個男人是烏龜。」眾人聽了，都大笑起來。薛蟠道：「笑什麼？難道我說的不是？一個女兒嫁了漢子，要做忘八，怎麼不傷心呢？」眾人笑的彎著腰，說道：「你說的是，快說底下的罷。」薛蟠瞪了瞪眼，又說道：「女兒愁－－」說了這句，又不言語了。眾人道：「怎麼愁？」薛蟠道：「繡房鑽出個大馬猴。」

Sources:

Cao, X., & Joly, H. B. (1892). Hung Lou Meng: Or, The Dream of the Red Chamber; a Chinese Novel – Book 2. Hongkong: Kelly & Walsh. Gulik, R. H. (1967). The Gibbon in China: An Essay in Chinese Animal Lore. Leiden: E.J. Brill.

Lam, H. L. (2005). Cannibalizing the Heart: The Politics of Allegory and The Journey to the West. In E. Ziolkowski (Ed.). Literature, Religion, and East/West Comparison (pp. 162-178). Newark: University of Delaware Press. Wu, C., & Yu, A. C. (2012). The Journey to the West (Vols. 1-4) (Rev. ed.). Chicago, Illinois: University of Chicago Press.