This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Nagual (Mesoamerica)
In Mesoamerican folk religion, a nagual or nahual (both from the Nahuatl word nahualli) is a human being who has the power to shapeshift into their tonal animal counterpart. Nagualism is tied to the belief one can access power and spiritual insight by connecting with the tonal animal within.
In some indigenous communities the nagual is integrated into the religious hierarchy. The community knows who is a nagual, tolerating, fearing and respecting them. Nagualli are hired to remove curses cast by other nagualli. In other communities the accusation of nagualism may result in violent attacks on the accused by the community.