Guardian of the forest
According to the legend, Curupira defends trees, plants, and animals against hunters, loggers, and anyone who damages the forest for its own sake. He is said to frighten intruders with sharp whistling calls and unsettling illusions, and his backward feet are supposed to leave tracks that lead pursuers the wrong way — a trick matched, in the stories, by a speed no human could outrun.
Storytellers also describe him luring young children into the forest, teaching them its secrets, and returning them to their families years later. Visitors who wander into his territory are said to become disoriented by his illusions while he watches, amused, from nearby.
Folklore, not fact
Curupira belongs squarely to oral tradition and has no basis in documented natural history; there is no scientific record of such a being. In some regions the tradition holds that leaving small offerings in the forest — food, arrows, tobacco — keeps him well disposed toward visitors, a detail that says more about the custom's roots in respect for the forest than about the figure's literal existence.