Pulgasari is based on a bull. He is exceedingly tall, and has a muscular body reminiscent of the Minotaur. He has long horns, and dark fur covering his body. His belly also appears to be protected by plates of gold-colored armor.
Pulgasari was created when a small monster figurine created by a blacksmith came in contact with the blood of the blacksmith's daughter, giving rise to the horned monster.
In feudal Korea during the Goryeo Dynasty, an evil emperor rules the land with an iron fist. He sends the villagers into misery and poverty. All seems hopeless, until a old blacksmith was sent to prison for unspecified reason. During his time at the jailhouse, he builds a small figure of a monster. When the small figure is splashed by the blood of the blacksmith's daughter Ami, it creates Pulgasari. Pulgasari starts eating metal, becoming bigger and stronger. Eventually he becomes powerful enough to try to take on the emperor. The emperor's guards first attempt to stop Pulgasari by imprisoning him in a cage which they then set on fire hoping it will burn him alive, but this is unsuccesful and the creature escapes in a fiery phase and kills the soldiers. The emperor's forces later attempt to defeat Pulgasari by burying him alive, but he manages to break free after Ami enpowers him with some more blood. Finally, the emperor and his army build cannons powerful enough in hopes they will kill the monster once and for all, but the kaiju is unaffected and kills the entire army in his way to the Emperor's chambers. Pulgasari finally kills the emperor and ends his wrath. Pulgasari starts to become a nuisance and turns on his creator. He begins to cause havoc at the villages, but Ami devises a plan. She tricks Pulgasari into eating her, causing Pulgasari to harden into a lifeless statue which then crumbles, out of which crawls Pulgasari's baby form, which is then sucked into Ami's lifeless body. The bull-like monster's terror has ended.
- In Korean, 불가사리 (Bulgasali) is also an euphony of "it can not be killed".
- Pulgasari's overall role and backstory appears to have been 'borrowed' from Daimajin:
- Both kaiju are spirits which can take a physical form.
- Both Daimajin and Pulgasari appear in a medieval setting, and are prized by the common people.
- Both Daimajin and Pulgasari attack the bourgeoisie of said medieval setting.
- After their work is done, both Daimajin and Pulgasari disappear, but not before threatening to cause chaos that affects the people who previously released them.