Hyōsubes are malevolent yokais (a type of supernatural creature) originating from Japanese folklore.
Hyōsube are related to another Japanese yokai called Kappa. Story tells of a warlord who built a shrine on a summit of a mountain for a battle god also named Hyōsube. The builders had crafted magical dolls to help in construction, but when the shrine was complete the dolls were discarded into a nearby river. There the magic resonated with Kappa magic, and the dolls became a twisted form of a Kappa - keeping the worst from their personality.
Said to stand no taller than a human child, the size of a Hyōsube should not be underestimated. They are dangerous creatures that are excessively hairy. Sometimes their head is entirely bald, and they have far more humanlike features than their origins, the Kappa. They have sharp teeth and claws well suited for combat. Hyōsube are also smelly, and tend to spread this stink wherever they leave their hair. Often this is in the baths of human people.
Possibly stemming from their rage of being discarded, the Hyōsube are violent and unpredictable, or maybe they retain some powers of the god of whom shrine they were used to build. They delight in causing severe damage to people's properties, and do not shun away from direct assault either. However, both physically and magically weaker than a Kappa, they have to pick their fights. They do remember some of the trickster nature of their origin species, and more often debilitate and harm rather than cause death.
The Hyōsube has a hatred towards horses that borders on irrational. Thus, if they can injure or kill a horse and at the same time cause trouble for people with with, all the better.
As for their habitat, they live inside underwater caves. During night they may rise from their abode and wreak havoc, or perhaps eat a field of eggplants (which are their favorite meal just like cucumber is for Kappas.)
Powers and weaknesses
Where Hyōsubes travel, a disease soon follows. Their hair is especially virulent towards horses. Disease carrying capabilities are not a consequence of their filthy living, and are definitely magical in nature. Their diseases have repercussions more akin to a curse than traditional disease as shown how a woman who drove off a Hyōsube from her field of eggplants fell ill and became purple as an eggplant before withering away. Other ways to have a lethal contagion is if catches a Hyōsubes laugh.
As for their weaknesses, they are less physically imposing than a Kappa is and can be more readily bested in a face-to-face fight, and lack direct magical abilities. They can be injured by conventional means, and can be easily distracted with eggplants.