Chivato
Within the Araucanian people of Chile, there is the chivito that is a cannibalistic monster. When he was a child he was taken by witches. From the years when taking he changed into a monster that had a taste for flesh. It was believed that was several chivatos that were believed that to live in the caverns beneath of Ancud and Chiloc. The tunnel can be accessed by the islanded lake. They prey on young women who come close to the lake.
John and Caitlin Matthews, The Element Encyclopaedia of Magical Creatures, 2013, Chivato, p 104