Mapinguari

According to Brazilian stories, the Mapinguari or Mapinguary was once an Amazonian shaman who discovered the key to immortality thousands of years ago. He angered the gods and was severely punished as to his discovery, which forced him to be transformed into a wandering beast for the rest of his life.

Modern sightings describe the beast as a giant sloth. Many cryptozoologists speculate that the Mapinguari is either a mylodontid or a megalonychid, medium-sized giant ground sloths from the Ice Age that lived in the area. The creature also supposedly has a horrid odor, which supposedly can knock a man unconcious.

Description
Tribal depictions and stories describe a humanoid creature with a mouth in the middle of its stomach. It is sometimes said to have one eye, long claws, caiman skin, backward feet and a second mouth on its belly. Modern sightings describe a giant, hairy ground sloth similar to the South American Megatherium or the North American Megalonyx. These creatures co-existed with the first Native Americans (Paleo-indians) and died out around 10,000 years ago, possibly due to over hunting. It is possible that the stories of Mapinguari are folk memory passed down for centuries about the once great creatures.