"And here come the Curupiras with their bright red hair and back-to-front feet. Tumbling, performing acrobatics, stealing hats from fans and generally creating mayhem, the stadium is greatly enjoying their antics."
-- Ginny Weasley, Daily Prophet, 11 July 2014 (QWC)
The Curupira is a human-like creature native to Brazil. Curupiras take the form of red-haired dwarves and live in the forests. Their feet point backwards and they are known to protect other forest creatures when these are threatened by humans.
The Curupira is the mascot of the Brazilian National Quidditch team. Curupiras contributed to the mayhem at the opening ceremony of the 2014 Quidditch World Cup when the mascots of the Fijian and Norwegian teams initiated a bloodbath and their protective instincts kicked in. A few months later, however, their playful display during the pre-match show that took place before the Brazil versus Bulgaria tournament final was greatly enjoyed by the crowd (QWC).
Curupira hair is said to be unstable for use in wands:
Curupira hair is a notoriously unstable wand core. However, if this wand chose you, you must be a very talented wizard, if unpredictable. https://t.co/4yxYIXyGfS
— J.K. Rowling (@jk_rowling) March 26, 2020
The name 'curupira' comes from the Tupi language kuru'pir, meaning "covered in blisters".
According to Brazilian folklore, the curupira uses its backward feet to create footprints that lead to its starting point, thus making hunters and travelers confused. They will prey on hunters and poachers that take more than they need, or who attack animals that are taking care of young. They can also create illusions and produce a high-pitched whistle that will drive its victim to madness (Wikipedia).