Before Sun Wukong became the protector of Tang Sanzang, he had another family.
Not by blood.
By oath.
Among the demon kings who once drank, fought, and called themselves brothers, one stood above the others as the eldest:
The Bull Demon King.
Centuries later, the friendship was gone.
Wukong had defeated his son. His wife hated the Monkey King. His family controlled the one treasure needed to cross the Flaming Mountains.
And when the old brothers finally met again, neither intended to surrender.
The Bull Demon King (牛魔王, Niú Mówáng) is one of the most powerful demon kings in Journey to the West. He is an old sworn brother of Sun Wukong, husband of Princess Iron Fan, father of Red Boy, a master of transformation, and the central opponent of Wukong during the battle for the Banana Leaf Fan.
Who Is the Bull Demon King?
The Bull Demon King appears surprisingly early in Journey to the West.
Before Wukong’s rebellion against Heaven, he befriends six powerful demon kings. When Wukong begins calling himself Great Sage Equal to Heaven, the others adopt grand titles of their own.
The Bull Demon King declares himself Pingtian Dasheng (平天大圣), commonly translated as the Great Sage Who Pacifies Heaven.
Later, Wukong explains that Bull Demon King was the eldest among their seven sworn brothers, while Wukong—being the smallest—ranked seventh.
But this was an ancient friendship.
By the time of Tang Sanzang’s pilgrimage, Wukong admits that hundreds of years have passed since the brothers were close. The relationship exists more as history than living loyalty.
That becomes important when Wukong meets the Bull Demon King’s family.
Bull Demon King Is Red Boy’s Father
Yes — Red Boy is explicitly the son of the Bull Demon King.
When Wukong investigates the demon who has captured Tang Sanzang, the local mountain and earth gods tell him that Red Boy is:
- the son of Bull Demon King;
- born to the Rakshasa Woman;
- known as Red Boy (红孩儿);
- titled the Sacred Infant Great King;
- a master of the terrifying Samadhi Fire.
Wukong initially thinks this family connection will solve the problem.
If Bull Demon King is his sworn brother, then surely Red Boy is basically his nephew.
Red Boy strongly disagrees.
Their conflict eventually ends when Guanyin subdues Red Boy and takes him as the Sudhana, or Good-Wealth Boy.
Red Boy survives—but his parents do not exactly thank Wukong for separating them from their son.
That old resentment becomes one of the reasons the Flaming Mountains conflict turns personal.
Princess Iron Fan and the Bull Demon King
The Bull Demon King’s wife is Princess Iron Fan, also called the Rakshasa Woman.
She possesses the Banana Leaf Fan, the treasure capable of extinguishing the supernatural flames blocking Tang Sanzang’s journey west.
When Wukong asks for it, she refuses partly because of what happened to Red Boy.
But Bull Demon King is no longer living regularly with her.
By this point in the novel, he has moved to Mount Jilei and is staying with Princess Jade Countenance, the daughter of the deceased Ten-Thousand-Year Fox King. The text says she brought considerable wealth into their relationship and chose Bull Demon King because of his tremendous supernatural abilities.
This gives Wukong a difficult problem.
He needs the fan.
Princess Iron Fan hates him.
And the man who might influence her is an old brother who now has several reasons to hate him too.
How Powerful Is the Bull Demon King?
Extremely.
And unlike many modern power-scaling claims, the original novel actually gives us plenty of evidence.
Bull Demon King possesses seventy-two transformations, just like Wukong. The narration also compares his martial ability directly with the Monkey King, although Wukong is described as more agile.
During their confrontation, the two repeatedly transform to counter one another.
Bull Demon King becomes creatures including a swan, hawk, crane, deer, leopard and bear.
Wukong answers each transformation with another predator or stronger form.
Eventually Bull Demon King stops playing.
He reveals his true form.
The Bull Demon King’s True Form
His original form is a gigantic white bull.
The novel deliberately makes the description enormous: his head is compared to a mountain ridge, his eyes flash, his two horns resemble iron towers, and his teeth are compared to blades.
The text even gives fantastically exaggerated dimensions—more than a thousand zhang from head to tail and hundreds of zhang in height.
This is not simply a normal ox.
It is the full monstrous body behind the demon king.
Wukong responds by expanding his own body to colossal size.
Their confrontation becomes so violent that the novel describes mountains shaking and Heaven and Earth being disturbed.
And still Bull Demon King refuses to surrender.
Bull Demon King vs Sun Wukong
This is what makes the character special.
Wukong does not simply arrive, swing the Ruyi Jingu Bang twice, and win.
Bull Demon King fights him for an extended period. Zhu Bajie eventually joins Wukong. Local divine forces intervene. More heavenly and Buddhist protectors surround the battlefield.
The novel itself has the Flaming Mountain deity describe Bull Demon King as possessing extraordinary supernatural power and being a genuine opponent for Wukong.
The Bull Demon King even tricks Wukong.
After Wukong finally acquires the Banana Leaf Fan, Bull Demon King transforms into Zhu Bajie, approaches him as though he were his fellow disciple, and tricks Wukong into handing the fan back.
Wukong—one of mythology’s greatest tricksters—gets tricked himself.
That alone tells us what kind of opponent he is facing.
How Is the Bull Demon King Defeated?
Eventually the conflict grows far beyond a duel.
Bull Demon King is surrounded by divine forces, including the Four Great Vajras and other celestial protectors. Li Jing and Nezha then arrive under heavenly orders.
Bull Demon King returns to his enormous white-bull form.
Nezha attacks him, repeatedly cutting off his head—but the demon simply grows another one. Nezha then places his fire wheels on the bull’s horns, while Li Jing uses the Demon-Revealing Mirror to prevent him from escaping through transformation.
Finally, Bull Demon King gives in.
He asks for his life to be spared and agrees to submit. Princess Iron Fan hands over the fan, allowing Wukong to extinguish the Flaming Mountains and continue the pilgrimage.
Why the Bull Demon King Matters
Bull Demon King is more than another monster blocking the road west.
He represents something rarer in Journey to the West:
Wukong’s past coming back to meet him.
They were once brothers.
Both became Great Sages.
Both mastered transformations.
Both built lives outside the ordinary human world.
But Wukong changed.
His journey forced him toward discipline, responsibility, and eventually enlightenment.
Bull Demon King remained tied to the old world of demon kings, personal grudges, power, and pride.
That is what makes their confrontation feel different from another monster fight.
Wukong is not merely defeating an enemy.
He is fighting someone who remembers who he used to be.
And perhaps that is why the Bull Demon King remains one of the most memorable rivals in the entire journey west.
Reference:
1. Journey to the West — Chapter 4
Bull Demon King е представен като един от старите sworn brothers на Sun Wukong и носи титлата Pingtian Dasheng.
