Sihuanaba
The Sihuanaba, La Siguanaba, Cigua or Cegua is a supernatural character from Central American folklore. It is a shape-changing spirit that typically takes the form of an attractive, long haired woman seen from behind. She lures men away into danger before revealing her face to be that of a horse or, alternatively, a skull.
The Siguanaba and its variants may have been brought to Latin America from Spain during the Colonial Period, used by the colonists as a means of exercising control over the indigenous and mestizo population.
Appearance
When encountered, she is a beautiful woman who is either naked or dressed in flimsy white; she usually appears bathing in a public water tank, river, or other water source, although she may also be found washing clothing. She likes to lure lone men out late on dark, moonless nights, without letting them see her face at first. She tempts such men away from their planned routes to lose them in deep canyons.
In Guatemala, the Siguanaba appears as a beautiful, seductive woman with very long hair. She will not reveal her face until the last moment, when it is revealed as either the face of a horse or, alternatively, a human skull. If her victim (usually an unfaithful man) does not die of fear then he is driven mad by the sight. From afar the Siguanaba can imitate the appearance of a man's girlfriend in order to lead him astray.