# Heibai Wuchang (黑白无常): The Black and White Impermanence > Heibai Wuchang, the Black and White Impermanence: who Xie Bi'an and Fan Wujiu are, what the white hat really said, and why Lu Xun loved the white one. Canonical: https://jadealmanac.com/chinese-mythology/heibai-wuchang Author: Julian (祝君瑜), Jade Almanac · https://jadealmanac.com/about Method and sourcing: https://jadealmanac.com/sources Heibai Wuchang, 黑白无常 (Hēibái Wúcháng), "Black and White Impermanence," are the two constables of the Chinese underworld who come with a chain to fetch the souls of the dying: a very tall, pale one dressed in white, with a long tongue and a tall hat, and a short, dark one dressed in black. Temples in Taiwan and Fujian call them Xie Bi'an and Fan Wujiu, two friends who died keeping an appointment under a bridge. They work for the City God and King Yama, and they are also, oddly, prayed to for money. They come in a pair, and they come on foot. One is absurdly tall and thin, dressed in white, with a hat as long as your forearm and a long tongue hanging out of his mouth; the other is short and stout and dressed in black, and he has the chain. In Chinese they are the Heibai Wuchang, 黑白无常, Hēibái Wúcháng, "Black and White Impermanence," and their job is to arrive at the bedside when your name comes up in the ledger, loop the chain over your neck and walk you down to the courts. Anyone who has walked into a City God temple knows the silhouette. And yet the same two figures stand in those temples with incense burning in front of them, and are prayed to by people who want nothing to do with dying, because they are also considered rather good for business. ## The tall one and the short one The white one is Bai Wuchang, White Impermanence; the black one is Hei Wuchang. The catalog record of a pair of carved statues in the National Museum of Taiwan History, in Tainan, gives the standard description: General Xie, tall and thin, his face pale, his long tongue out, a tall hat on his head; General Fan, short and stout, his face dark; the two of them holding fire-tallies and command plaques, the warrants and badges of men sent to make an arrest. They are, the record says, the soul-catching messengers of the underworld, and they serve as assistants to the gods who judge: the God of Mount Tai, the [City God](/chinese-mythology/city-god), the royal lords called Wangye. What you call them depends on where you grew up. In Taiwan they are Qiye and Baye, Seventh Master and Eighth Master, or Tall Master and Short Master. Hokkien speakers in Singapore and Malaysia call them Tua Ya Pek and Di Ya Pek, First Uncle and Second Uncle. In Lu Xun's Shaoxing a century ago the white one was simply Huo Wuchang, Living Impermanence. On the mainland they are most often just the Black and White, said together, the way English says salt and pepper. Where they sit in the hierarchy matters, because it explains almost everything about them. The Japanese folklorist Ōtani Tōru, who has written a whole book about the pair, *China's God of Death* (2023), puts it plainly in an interview with Real Sound: at the top of the underworld sits a great judge with the ledger of life-spans; orders pass down through the courts; and at the very bottom, the men who actually knock on the door, are the Wuchang. They are often enshrined, he notes, in a corner of the City God's temple or the God of Mount Tai's, not in the main hall. [King Yama](/chinese-mythology/king-yama) signs the warrant. The Black and White serve it. ## Seventh Master and Eighth Master at the head of the parade If you want to see them move, go to Taipei in early summer. The Xia-Hai City God, whose temple in the old Dadaocheng district is, in the words of the city tourism office, one of the most historic spots in Taipei, has his birthday on the fourteenth day of the fifth lunar month, usually in June, and on the eve of it he is carried around the neighborhood in a parade. The Taipei City Government's tourism office describes the god's "army" marching with him: Generals Fan and Xie, "also known as Grandfathers Seven and Eight," two of the "tall gods" that walk in Taiwanese temple parades. These are giant figures, worn by a performer inside, the white one towering a couple of heads above the crowd, the black one squat and wide, both swaying side to side with a long-armed swagger that nobody who has seen it forgets. A temple representative explained to the tourism office why the parade is held the day before: the god "shouldn't travel on his birthday." They are at the front for a reason. They are the police. When a magistrate goes out on circuit, his constables clear the road, and when the City God goes out to inspect his city's ghosts, the Black and White go first. ## Tua Ya Pek's temples In Singapore and Malaysia the pair have done something remarkable: they have become the center of their own cult. The anthropologist Fabian Graham, writing in *Cultural Diversity in China* in 2016, describes the rapid growth since the mid-1990s of temples in Singapore built around spirit mediums who go into trance and are possessed by Tua Ya Pek and Di Ya Pek, the two underworld deities, so that worshippers can speak to them directly. The cult's teaching is about earthly morality and punishment after death, and it has, Graham notes, its own distinct ritual and material culture. The constables of hell, in other words, take questions. Ōtani's fieldwork explains the route. He calls Fujian province, the coast facing Taiwan, the Mecca of Wuchang belief, and traces the pair's spread to the Fujianese who emigrated to Taiwan and Southeast Asia, taking their temples with them. That is why Jade Almanac readers in Singapore or Penang are more likely to have met the Black and White in person than readers in Beijing. ## A god of death who is also good for business Here is the paradox that makes the pair so beloved. They are the lowest rank in the underworld, and that is exactly the point. Ōtani's explanation is simple: a great god is distant and hard to petition, a junior one is approachable, the way you might find it easier to ask a favor of the clerk than of the judge. And the Black and White have a reputation, he says, as an auspicious sign that sometimes brings a large sum of money. Meeting the white one is bad news if he has come for you, and very good news if he has not. Hence the hat. On most statues and souvenirs today the white one's hat bears four characters, *yī jiàn shēng cái*, "one look and you'll make money," and the black one's reads "peace under heaven." If you want the full measure of how Chinese folk religion works, it is this: the figure who comes to drag you to hell has a blessing for prosperity written on his forehead, and nobody finds this strange. As we shall see further down, it was not always what the hat said. ## Two souls in an umbrella, and a heroine called Wuchang Most English-speaking readers meet the pair in a video game. In October 2018 the Chinese studio NetEase added a hunter called Wu Chang to *Identity V*, its four-against-one survival horror game, announcing it as "a new hunter character created with a traditional Chinese story." The character is both constables at once, the White Guard and the Black Guard sealed in a single umbrella, switching from one to the other mid-chase. The umbrella is not a random prop. In one version of the temple legend below, Xie Bi'an is late to the bridge because he has gone to borrow an umbrella in the rain. Then, in July 2025, came *WUCHANG: Fallen Feathers*, a punishingly difficult action game from the Chinese studio Leenzee, published by 505 Games, set in the province of Shu at the end of the Ming dynasty. Its heroine, a pirate struck by amnesia and afflicted by a disease the game calls the Feathering, is called Wuchang. The publisher reports more than five million players. Whether the studio meant the white-hatted constable or only the Buddhist word underneath him, it has not said in English, and the name carries both. A heroine who cannot remember her past, named Impermanence, in a game full of the dead: a Chinese reader takes the hint whether or not it was intended. (She would, in any case, have had to get past [Meng Po](/chinese-mythology/meng-po) to forget anything.) ## Xie Bi'an and Fan Wujiu: the story the temples tell The pair have names, and the names come with a story. It is not in any classical book. It is told in the temples of Fujian and Taiwan, in several versions, of which this is the commonest. Xie Bi'an and Fan Wujiu were two constables in a magistrate's office, as close as brothers. One day, escorting a prisoner, they lost him, split up to search, and agreed to meet again under a certain bridge. It began to rain. Xie was held up; in some tellings he had gone to borrow an umbrella. Fan reached the bridge on time and waited. The river rose. Fan would not leave, because he had given his word, and he drowned under the bridge. When Xie finally arrived and found his friend gone, he hanged himself from the bridge. The Jade Emperor, moved by a loyalty that would keep an appointment past the point of death, appointed the two of them constables of the underworld. The legend then explains the iconography, piece by piece. Fan drowned, so his face is black. A hanged man's tongue hangs out, so Xie's does: the record of the General Xie statue at the Yanshui Dazhong Temple in Tainan says it flatly, that Seventh Master died by hanging, and so the long tongue became his chief feature. Ōtani is more careful. A protruding tongue, he points out, is an old device for frightening off evil spirits, and the hanging story may have been fitted to the face rather than the face to the story. The names are puns, and the same Taiwanese records spell them out. Xie Bi'an sounds like "make amends and you will surely be at peace." Fan Wujiu sounds like "commit a crime and there is no saving you." So the pair are a sermon in two words, the carrot walking beside the stick, which is about as neat a piece of folk theology as you will find. They are also a very Chinese kind of hero: two minor officials, nobody's idea of a god, deified for keeping their word. ## What the hat actually said Now the part the internet does not know. In 1926 the writer Lu Xun, the most famous Chinese author of the twentieth century and not a man given to sentiment about religion, wrote an essay called simply "Wuchang," about the white one, whom he had loved as a boy in Shaoxing. Lu Xun was fussy about sources, and he tells us where to look: the illustrated editions of the Jade Record, the Qing morality book that furnished every temple's picture of hell. There, he says, the white one wears "the coarse sackcloth of the deepest mourning, a straw rope around his waist, straw sandals on his feet and paper money hung around his neck," and carries a broken palm-leaf fan, an iron chain and an abacus, his brows sloping down at the ends. And on the front of the tall hat, "four characters are written straight down: 'One look, and a happy event.'" "In one edition, though," Lu Xun adds, "it says: 'So you've come too.'" So the hat did not originally promise money. It made a joke. "So you've come too" is the welcome of a man who has met everybody: the emperor, the beggar, and now you. And "a happy event" is the kind of joke only a culture with a sense of humor about funerals could make. A Chinese wedding is a red happy event; the funeral of someone who has lived to a good old age is a white one. A ghost dressed in white mourning, whose hat promises a happy event, is announcing a white happy event, which is to say your funeral. That reading is mine, not Lu Xun's; he only says that he never found out who wrote the words, "the Wuchang himself or King Yama." | Where | What the white hat says | In English | |---|---|---| | The Jade Record prints, as Lu Xun describes them (1926) | 一見有喜 | One look, and a happy event | | "One edition," per Lu Xun | 你也來了 | So you've come too | | Statue record, National Museum of Taiwan History | 一見大吉 | One look, great luck (on other statues: one look, get rich) | | Most temples and souvenirs today | 一见生财 | One look and you'll make money (the black hat: peace under heaven) | At some point between Lu Xun's boyhood and the souvenir stall, "a happy event" became "great luck" and then "you'll make money," and the grim joke turned into a blessing. Exactly when, and how, nobody has documented. The abacus may have helped. Whatever it was counting in the underworld, a shopkeeper who sees an abacus thinks of the till. ## Two demons at the bridge The Jade Record itself is stranger still, because in its text the colors are the other way round. At the very end of the underworld, after the soul has drunk Meng Po's soup and been pushed onto a bamboo bridge over a river of red water, the Jade Record's tenth court produces two demons. "One wears a black gauze cap and a brocade jacket," it says, "holds paper and a brush," a knife stuck behind his shoulder, "his eyes are stretched round and he roars with laughter; his name is Living Impermanence." The other "has a filthy, bleeding face and wears a white shirt; he holds an abacus in both hands," with a rice sack on his back and paper money on his chest, "his brows are knotted and he sighs and sighs; his name is Death-Has-Its-Share." Then they shove the souls off the bridge into the river and into their next lives. Read that again with the familiar pair in mind. In the book, the one in white with the abacus and the drooping brows is Death-Has-Its-Share, and the one called Wuchang wears black and laughs. In Lu Xun's prints and his Shaoxing processions, Living Impermanence is the one in white with the abacus, and the black one is his counterpart. Lu Xun saw the drift happen: the Jade Record's Death-Has-Its-Share, he says, turned up in the processions too, "but there his name has been garbled into 'Dead Impermanence': black face, black clothes, and nobody likes looking at him." Lu Xun warns that the Jade Record existed in fuller and briefer editions, so the pictures and the text may simply have parted company. Either way, the two texts together suggest how the pair was made, though no one wrote the moment down: one ghost with a Buddhist name, one ghost with a grim proverb for a name, and the proverb-ghost lost his name to the first, and they became the Black and White Impermanence. ## Lu Xun's favorite ghost Lu Xun's essay is the best thing ever written about the white one, and it is worth knowing why he loved him. In Shaoxing, he says, people knew Wuchang better than any other ghost. In the City God's temple there was a dark room of underworld statues, and the long white thing you saw first as you came in was him, chain in hand. One temple nearby had once rigged the floor so that stepping on a loose plank swung the statue forward and dropped the chain over your neck, until it frightened a man to death and they nailed it down. And yet when the processions came through town and the tall white paper hat appeared above the crowd, Lu Xun writes, everyone grew tense and happy at once. The reason was the opera. Shaoxing's all-night Mulian operas, staged to drive off misfortune, always had a villain whose sins caught up with him at dawn, and when King Yama sent the warrant, Wuchang came on stage to collect him: powdered face, red lips, black brows knitted so that you could not tell if he was laughing or crying. Before he could say a word he had to sneeze a hundred and eight times and break wind a hundred and eight times, and only then did he sing his résumé. Lu Xun gives the song in the Shaoxing dialect. The King sent him to fetch the scabby fellow next door, who turned out to be his own cousin's boy, sick with typhoid and dysentery, dosed by a doctor's useless son with "aconite, cinnamon bark, and ox-knee root besides." The first dose brought out a cold sweat. The second dose, "both his legs went straight." And then the line Lu Xun built his essay around: "I said, our sister-in-law is weeping so, I'll let him go back to the living for half a quarter-hour. The King said I'd taken a bribe to let him off, and had me tied up and given forty strokes!" So the white one learned. He dances, a strange duck-paddle of a dance with his broken fan, his face to the ground, and swears off mercy for good: "Now I let nobody go! Not if you are a wall of bronze and iron! Not if you are kin to the emperor!" That is why the poor of Shaoxing loved him, Lu Xun says. In this world there was no justice for people like them; in the next there would be, and the man who came to fetch them was the one official who had once broken the rules for a crying woman, and been beaten for it. "Of all the host of ghosts," he wrote, "he alone has a little human feeling." He records, too, the processions in which the white one was given a wife, a pretty country girl everyone called Mrs. Wuchang, and a little son in a little tall hat with his shoulders already hunched, called A-Ling; and the custom of laying out a meal of wine and rice for him whenever someone in the house died, to see him off politely. He ends by calling the white one a creature who was "a ghost and yet a man, justice and yet feeling, dreadful and yet lovable." ## A Buddhist word in a tall hat The name is older than the ghosts. *Wúcháng* is the Chinese translation of the Sanskrit *anitya*, impermanence, the first of the marks of existence in Buddhist teaching. Its most famous statement in Chinese is the Snow Mountain verse of the *Nirvana Sutra*, which Ding Fubao's *Dictionary of Buddhist Studies* of 1922 calls the outline of the whole of Buddhism: "All conditioned things are impermanent; they are things that arise and pass away. When arising and passing away have ceased, that stillness is bliss." The idea became a proverb, "life is impermanent," and the proverb, at some point, put on a tall hat and came to the door. Lu Xun, who had looked, could find no ancestor for the soul-catcher in the old books. The Indian sutras gave China its King Yama and its ox-headed jailers, he notes, but the messenger who hooks away the living "seems to have no warrant in antiquity." His conclusion: "Probably, once the idea reached China, people gave it a body. He really is a creation of us Chinese." Ōtani, a century of research later, refines this rather than overturns it: there were soul-catching messengers in Chinese stories as early as the Six Dynasties, fifteen hundred years ago, but they were faceless officials with no personality. Only later did they take the name of impermanence, and later still the tall hat, the tongue, the jokes and the fan. Where the hat came from, Ōtani admits, is still a mystery; his guess is the headgear of Chinese mourners. So the Black and White are a word that became a pair of men. They sit at the bottom of the same divine civil service as the humble [Tudigong](/chinese-mythology/tudigong), the village Earth God, and they share his virtues: they are local, they are junior, they can be bargained with, and they have a story you can tell a child. Nearly every other figure in the Chinese underworld is a judge, a jailer or a torturer. These two are the ones who knock on the door, and the Chinese, given the chance to imagine death, decided it should be a pair of old colleagues who once drowned and hanged for each other, one of whom got forty strokes for being kind. Dreadful and yet lovable. You could do worse, at the end, than be fetched by a friend. ## Primary sources - Lu Xun, 'Wuchang' (无常), in Dawn Blossoms Plucked at Dusk (朝花夕拾), the hat and the costume, from the illustrated Jade Record, tr. Jade Almanac, from the original (the standard English version is Yang Xianyi and Gladys Yang's, Foreign Languages Press), 1926 > 身上穿的是斬衰兇服，腰間束的是草繩，腳穿草鞋，項掛紙錠；手上是破芭蕉扇、鐵索、算盤；肩膀是聳起的，頭髮卻披下來；眉眼的外梢都向下，象一個“八”字。頭上一頂長方帽，下大頂小，按比例一算，該有二尺來高罷；在正面，就是遺老遺少們所戴瓜皮小帽的綴一粒珠子或一塊寶石的地方，直寫著四個字道：“一見有喜”。有一種本子上，卻寫的是“你也來了”。 > He wears the coarse sackcloth of the deepest mourning, a straw rope around his waist, straw sandals on his feet and paper money hung around his neck; in his hands are a broken palm-leaf fan, an iron chain and an abacus; his shoulders are hunched up, but his hair hangs loose; the outer ends of his brows and eyes all slope downward, like the character for "eight." On his head is a long square hat, wide at the bottom and narrow at the top, which by proportion must be about two feet tall. On the front of it, just where the old diehards sew a pearl or a gem onto their melon-rind skullcaps, four characters are written straight down: "One look, and a happy event." In one edition, though, it says: "So you've come too." https://zh.wikisource.org/wiki/無常 - Lu Xun, 'Wuchang' (无常), the black one, and where the pair came from, tr. Jade Almanac, from the original, 1926 > 《玉歷鈔傳》上還有一種和活無常相對的鬼物，裝束也相仿，叫作“死有分”。這在迎神時候也有的，但名稱卻訛作死無常了，黑臉、黑衣，誰也不愛看。……至於勾攝生魂的使者的這無常先生，卻似乎於古無征，耳所習聞的只有什麽“人生無常”之類的話。大概這意思傳到中國之後，人們便將他具象化了。這實在是我們中國人的創作。 > The Jade Record also has a ghost who is the counterpart of Living Impermanence, dressed much the same, called Death-Has-Its-Share. He turns up in the processions too, but there his name has been garbled into "Dead Impermanence": black face, black clothes, and nobody likes looking at him. ... As for this Mr. Impermanence, the messenger who hooks away the souls of the living, he seems to have no warrant in antiquity; all one ever hears is talk of "life is impermanent" and the like. Probably, once the idea reached China, people gave it a body. He really is a creation of us Chinese. https://zh.wikisource.org/wiki/無常 - Lu Xun, 'Wuchang' (无常), the white one's song in the Mulian opera, tr. Jade Almanac, from the original, 1926 > 大王出了牌票，叫我去拿隔壁的癩子。問了起來呢，原來是我堂房的阿侄。生的是什麽病？傷寒，還帶痢疾。看的是什麽郎中？下方橋的陳念義la兒子。開的是怎樣的藥方？附子、肉桂，外加牛膝。第一煎吃下去，冷汗發出；第二煎吃下去，兩腳筆直。我道nga阿嫂哭得悲傷，暫放他還陽半刻。大王道我是得錢買放，就將我捆打四十！……難是弗放者個！那怕你，銅墻鐵壁！那怕你，皇親國戚！ > The King sent out a warrant: go and fetch the scabby fellow next door. I asked around, and he turned out to be my own cousin's boy. What was he sick with? Typhoid, and dysentery on top. Which doctor did he see? Chen Nianyi's son, from Xiafang Bridge. What was the prescription? Aconite, cinnamon bark, and ox-knee root besides. The first dose went down, and out broke a cold sweat; the second dose went down, and both his legs went straight. I said, our sister-in-law is weeping so, I'll let him go back to the living for half a quarter-hour. The King said I'd taken a bribe to let him off, and had me tied up and given forty strokes! ... Now I let nobody go! Not if you are a wall of bronze and iron! Not if you are kin to the emperor! https://zh.wikisource.org/wiki/無常 - The Jade Record (玉历宝钞), the Tenth Court, the two demons at the bridge of rebirth, tr. Jade Almanac, from the original, Qing dynasty (the text claims a Song origin) > 對岸跳出長大二鬼分開撲至水面，兩徬站立不穩。一個是頭蓋烏紗，體服錦襖，手執紙筆，肩插利刀，腰褂刑具，撐圓二目，哈哈大笑，其名『活無常』。一個是垢面流血，身穿白衫，手捧算盤，肩背米袋，胸懸紙錠，愁緊雙眉，聲聲長嘆，其名『死有分』。 > From the far bank two huge demons leap out, one on either side, and lunge at the water so that the souls cannot keep their footing. One wears a black gauze cap and a brocade jacket, holds paper and a brush, has a sharp knife stuck behind his shoulder and instruments of punishment hung at his waist; his eyes are stretched round and he roars with laughter; his name is Living Impermanence. The other has a filthy, bleeding face and wears a white shirt; he holds an abacus in both hands, carries a sack of rice on his back and paper money on his chest; his brows are knotted and he sighs and sighs; his name is Death-Has-Its-Share. https://zh.wikisource.org/wiki/玉歷寶鈔 - Nirvana Sutra (大般涅槃经), juan 14, as quoted in Ding Fubao's Dictionary of Buddhist Studies (佛学大辞典), the verse of impermanence, also called the Snow Mountain verse, tr. Jade Almanac, from the original, sutra translated into Chinese in the 5th century; dictionary 1922 > 諸行無常，是生滅法，生滅滅已，寂滅為樂。 > All conditioned things are impermanent; they are things that arise and pass away. When arising and passing away have ceased, that stillness is bliss. https://zh.wikisource.org/wiki/佛學大辭典/諸行無常 ## Pop culture appearances - Identity V (第五人格) · game · 2018 · released · A playable hunter built on the pair: two souls, the White Guard and the Black Guard, sealed in one umbrella, switching forms mid-match; NetEase's announcement calls it a character 'created with a traditional Chinese story' · Wu Chang (Xie Bi'an / Fan Wujiu) · Added in the October 2018 update; the game's lore keeps the temple legend of the drowning under the bridge. - WUCHANG: Fallen Feathers · game · 2025 · released · A soulslike set in Shu at the end of the Ming dynasty, whose amnesiac heroine is named Wuchang; the studio has not said in English whether the name points at the underworld constables or only at the Buddhist word · Wuchang · Developed by Leenzee, published by 505 Games; the publisher reports more than 5 million players. ## Sources - Lu Xun, 'Wuchang' (無常), from Dawn Blossoms Plucked at Dusk, 1926 (Chinese Wikisource): https://zh.wikisource.org/wiki/無常 - The Jade Record (玉歷寶鈔), full text, with the two demons at the bridge in the Tenth Court (Chinese Wikisource): https://zh.wikisource.org/wiki/玉歷寶鈔 - Ding Fubao, Dictionary of Buddhist Studies (佛學大辭典), 1922, entry on the verse of impermanence (Chinese Wikisource): https://zh.wikisource.org/wiki/佛學大辭典/諸行無常 - National Taiwan Museum of History, carved wooden statues of Generals Xie and Fan, catalog record (National Culture Memory Bank, Taiwan Ministry of Culture): https://tcmb.culture.tw/zh-tw/detail?indexCode=MOCCOLLECTIONS&id=11000121827 - General Xie of the Yanshui Dazhong Temple, Tainan: names, legend and role (National Culture Memory Bank, Taiwan Ministry of Culture): https://tcmb.culture.tw/zh-tw/detail?indexCode=Culture_Object&id=733700 - Taipei City Government, Department of Information and Tourism, on the Xia-Hai City God's birthday parade (Taipei Travel, 2022): https://travel.taipei/en/pictorial/article/36050 - Fabian Graham, 'The Temple of Mysterious Virtue', Cultural Diversity in China 2:1 (2016), on Tua Ya Pek and Di Ya Pek spirit-medium temples in Singapore: https://reference-global.com/article/10.1515/cdc-2016-0003 - Real Sound Book, interview with the folklorist Ōtani Tōru on his book China's God of Death (中国の死神, Seikyusha), 2023 (Japanese): https://realsound.jp/book/2023/10/post-1460053.html - NetEase, 'Identity V Gets Major Update with New Game Mode and an Interactive Map', press release, 1 October 2018: https://pressreleases.triplepointpr.com/2018/10/01/identity-v-gets-major-update-with-new-game-mode-and-an-interactive-map/ - WUCHANG: Fallen Feathers, store page and publisher announcements (Steam): https://store.steampowered.com/app/2277560/ - Heibai Wuchang (Wikipedia): https://en.wikipedia.org/wiki/Heibai_Wuchang ## FAQ **What is Heibai Wuchang?** Heibai Wuchang (黑白无常), "Black and White Impermanence," is the name for the two ghost constables of Chinese folk religion who come to arrest the souls of the dying and escort them to the underworld. The white one, Bai Wuchang, is tall and pale with a long tongue and a tall hat; the black one, Hei Wuchang, is short and dark and carries a chain or a tablet. They serve the judges of the dead, the City God, the God of Mount Tai and King Yama, and appear in temple statues, processions and opera. Lu Xun, in his 1926 essay on them, called the pair a purely Chinese invention. **What is the story of Xie Bi'an and Fan Wujiu?** It is the legend told in Taiwanese and Fujianese temples. Xie Bi'an and Fan Wujiu were two constables, close as brothers, who agreed to meet under a bridge. Rain held Xie up; Fan would not break his word, stayed under the bridge as the river rose, and drowned, which is why his face is black. Xie arrived, found him gone, and hanged himself from the bridge, which is why his tongue hangs out. The Jade Emperor, moved by their loyalty, made them constables of the underworld. The names are puns recorded by Taiwan's National Culture Memory Bank: Xie Bi'an, "make amends and you will surely be at peace," and Fan Wujiu, "offend and there is no saving you." **What does the writing on Bai Wuchang's hat mean?** The modern hat usually reads 一见生财 (yī jiàn shēng cái), "one look and you'll make money," and the black hat 天下太平, "peace under heaven." Older versions differ. Lu Xun, describing the Jade Record prints of the early twentieth century, says the white hat read 一見有喜, "one look and a happy event," and in one edition "So you've come too." A statue record from Taiwan's National Museum of History gives "one look, great luck" or "one look, get rich." How the joke turned into a blessing nobody has documented. **Why does Bai Wuchang have a long tongue?** The usual answer comes from the temple legend: Xie Bi'an, the white one, hanged himself after his friend drowned, and a hanged man's tongue hangs out. A record of the statue at the Yanshui Dazhong Temple in Tainan says exactly that. The Japanese folklorist Ōtani Tōru adds a caution: a protruding tongue is also an old device for scaring off evil, so the hanging story may have been fitted to the image rather than the other way round. **Are Heibai Wuchang good or evil?** Neither. They are functionaries, the lowest rank of the underworld's police, and they arrest everyone whose time is up, good or bad. That makes them frightening and, oddly, approachable: Ōtani Tōru, who has studied them in Fujian, notes that a god this junior is easier to petition than a great one, and they are prayed to for luck and wealth. Lu Xun thought the white one the only ghost in the underworld with human feeling. **Is Hei Bai from Avatar based on Heibai Wuchang?** No. Hei Bai, the forest spirit in the first season of Avatar: The Last Airbender, takes its name from the same two Chinese words, "black white," and in its calm form it is a giant panda, the most famous black-and-white animal in China. The underworld constables are a different black and white entirely: a pair of men, one in each color, who come for the dying.