Have you ever heard that elephants are scared of mice? Or that foxes are sly? These characterizations of animals come from a medieval book called the Bestiary, or Book of Beasts, Khan Academy says. Though this book is not known to many today, you are likely familiar with some of the content. The magical beasts in the Harry Potter series, for example come directly from medieval bestiaries. Descriptions of unicorns, phoenixes, basilisks, and centaurs are all included in the text. The Abarimon are found there too.
According to warriorsofmyth, the Abarimon is a creature with origins in Greek and Roman mythology, legend and folklore. Their existence was first documented in texts from Ancient Greece (specifically by Megasthenes)
According to Wikipedia, Abarimon or the ‘antipode,’ are mythological humanoids whose feet are turned backwards, but in spite of this, are able to run at great speeds.
The earliest recordings of the creature occurred in Europe. This tribe was first described by Pliny the Elder, in his book, Natural History (VII 11), and he considered them to be native to the general area of India. A similar tale is recounted by Aulus Gellius in Attic Nights.
The Abarimon lived side by side with wild animals and were wild themselves. Attempts at capturing them failed because they were so savage. Pliny the Elder actually in retelling a story that originated with Baiton, ( Alexander the Greats Land Surveyor,) says that the abarimons only breathed the air in their own domestic valley. Because of the special quality of their air, it would be impossible to breathe any other type. Therefore these inhabitants were unable to leave the valley. So it was further an impossibility to capture them and bring them to the courts of a distant ruler, which would have happened if they were able to be caught or to live past their borders. 
Natural phenomena, becoming Myth?
It is possible, of course that this is an overly exaggerated ethnographic description of an actual ancient wildlife species in the areas near the Himalayas.According to another legend, the Abarimon is mentioned as merely a landscape in Scythia, a valley of ‘Mount Imaus,’ (which would have been the Hindukush or the Himalayan Mountains).
The Abarimon is famously strange, and few would be comfortable to see such a sight. Backwards feet?…backwards feet that are functional, no less. Many are jealous of this savage creatures apparent “leg up,” on the competition. The Medieval Bestiary… the oldest known copy ‘lives,’ in Scotland as an artifact. It is there, in The National Museum of Scotland that the Beasts from the Bestiary come out at night to play…a la Night at the Museum. The air quality thing wasn’t true and so they are there too… with the Griffins and the Basilisk. The Abarimon are the undefeated sprinting champs in the museum, but they are about to meet their match. Tell us about the Abarimon’s competition? Who is this new kid on the block?
If you find this fun and interesting and decide to expand on it- let me know how this story continues in the comment section below, and as usual…happy writing!