This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Sagari (Japanese)
Sagari is a strange apparition from West Japan and Kyushu, particularly Okayama and Kumamoto prefectures. It takes the form of a grotesque horse’s head, which drops down from hackberry trees to startle travelers on the road. Sagari come from the spirits of horses which die on the road and are discarded and left to rot where they fall.
The horses’ souls sometimes get caught in the trees as they rise from the bodies. The ones that stick in the trees cannot pass on to the next word and transform into these yokai. Those who hear it whinnying and screaming are stricken with a terrible fever.