This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Peuchen (Chilota and Mapuche)
The Peuchen (also known as Piuchen, Pihuchen, Pihuychen, Pihuichen, Piguchen, or Piwuchen) is a creature from the Mapuche mythology and Chilote mythology pertaining to southern Chile, a much feared shapeshifting creature that can instantly change into animal form. According to legend, El Peuchen takes the hearts of its victims without leaving a mark on the body.
It has often been described as a gigantic flying snake which produced strange whistling sounds, while its gaze could paralyze an intended victim and permit it to suck its blood. It has often been reported as the cause of blood being sucked from one's sheep. The creature can be eliminated by a machi (Mapuche herbal healer).