THE MAPUCHE EVIL RAT.

The Colo Colo is a shape-shifter evil-rat creature from Mapuche mythology originated from the Chiloe Archipelago, in Southern Chile.
The appearance of the Colo Colo varies depending on the region where the myth is told. Sometimes it is described as having the crest of a rooster and the body of a serpent. Other times as a feathered rat, or as a snake or lizard with a rat's head, and occasionally it is just depicted as a huge rat.
According to a legend, the Colo colo hatches from an egg laid by a snake that is incubated by a rooster. After hatching, the Colo Colo will hide in a house, commonly living in a hole which it digs under it, or at the corners or cracks found in it.
The Colo Colo will feed by taking the saliva or phlegm from the sleeping people who live in the house, causing the inhabitants to dehydrate, feel exhausted, and make them susceptible to several serious diseases that eventually will take the life of the person.
The Colo Colo can be detected if someone of the house is feeling tired for no reason, or of its cry, which is similar to an infant wailing. Also if a Colo Colo is present it will also produce a very distinct, foul smell.
When a Colo Colo is in the house, a traditional healer (Machi) and religious leader must be contacted to exorcise the premises. He must burn the egg as soon as it is laid and kill the chicken that laid it, to prevent further eggs from being laid. Once hatched, sometimes the only way to destroy it is by burning  down the house where it lives, because its energy is vulnerable to Fire.
Colo Colo are believed to attack their human prey while they sleep. The monster prefers to bite the tongue of it's sleeping prey and then proceeds to drain the victim of it's saliva, body fluid, and life force.
Accoding to some sources human brains may also be consumed. The victims of Colo Colo can be identified by their "zombie" or trance-like state. If repeat attacks occur on the same person he/she will eventually die.