According to legend, the curse does not begin with an animal but with a human woman. Folk belief influenced by Catholic doctrine claimed that any woman who entered a forbidden romantic relationship with a priest would be condemned to this fate. Her punishment was not death, but transformation. On a Thursday night as Friday approaches, a dark force overtakes her body, and she is drawn helplessly to a crossroads, a place believed to tear the soul between worlds. There, her humanity is stripped away, and she becomes the Headless Mule.
The creature’s appearance is said to be pure terror made flesh. It has the body of a powerful mule, but where its head should be, endless flames erupt from its neck, burning bright red and never fading. The fire lights up roads and fields as it charges through the night, scorching anything too close. Though it has no mouth, it releases deafening screams, a chilling mix of animal shrieks and a woman’s agonized cries, echoing across villages and forests.
As it runs, its iron or bronze hooves strike the ground, sending sparks flying and announcing its arrival long before it is seen. Some versions of the tale describe a broken silver bridle dragging from its neck, scraping against stone and earth, producing a metallic sound that freezes listeners in fear. Wherever those sounds are heard, people know destruction soon follows.
The Headless Mule is said to race through seven villages or seven crossroads in a single night, trampling animals, burning fences, and terrifying anyone who crosses its path. No one is meant to stop it, yet folklore offers rare ways to break the curse. One method requires a brave soul to stab the beast with a steel pin until a single drop of blood falls. At that moment, the flames vanish, and the woman returns to human form, weak, naked, and weeping in shame. Another method involves tearing away the silver bridle, but without true repentance, the curse will return the following Thursday night.
At its heart, the legend of the Headless Mule is a harsh moral lesson. It was created to condemn forbidden relationships and protect religious authority in a rigid society. The burning fire in place of a head symbolizes reason destroyed by sinful desire, while the endless running reflects a soul trapped by guilt and fear.
The story also reveals the deep imbalance of social judgment in the past. While sin was shared, punishment fell almost entirely on women, turning them into monsters in the public imagination. Through fear and legend, communities enforced obedience, morality, and silence.
Even today, Mula sem Cabeça remains a powerful symbol in Brazilian folklore, a reminder of how fear, belief, and social control can shape myths, and how stories once used to warn can also expose the injustices of the world that created them.