Nekomata

Nekomata are a malevolent yokai from Japanese folklore and mythology, belonging to the neko class of animal spirit - like all neko the Kasha are envisioned as a type of demonic feline but are distinguished from other neko by the fact they always have two tails, they are also considered the most evil of all neko spirits and thus much like beldams in Western legend they are completely devoted to wicked-doing in all its forms and have no redeeming qualities whatsoever, a classic "fairy tale" demon that exists solely to cause cruelty and fear.

Nekomata have a vast array of magical abilitues and often begin life as ordinary housecats who, upon reaching a great age, develop great intelligence and supernatural traits - if their tail splits in two they have become a Nekomata and will normally establish themselves via devouring their former owner and taking their form.

Nekomata will then begin their immortal life as a servant of unfettered evil, devouring humans whenever they can, causing massive fires and raising the dead as "puppets" for their amusement - they also continually gain social status via treachery and murder so as to use their new status to blackmail or enslave others.

Nekomata are believed to only form from very old and very large cats with exceptionally long tails, for this reason many cats were feared in ancient Japan (though some were revered and seen as good luck) and it was not uncommon for practices such as the cutting of cat tails to try and prevent the creation of such demons.