The bakeneko (化け猫, "changed cat") is a type of Japanese yōkai, or supernatural creature. According to its name, it is a cat that has changed into a yōkai. It is often confused with the nekomata, another cat-like yōkai, and the distinction between the two can often be quite ambiguous.
There are legends of bakeneko in various parts of Japan, but the tale of the Nabeshima Bakeneko Disturbance in Saga Prefecture is especially famous.
The reason that cats are seen as yōkai in Japanese mythology is attributed to many of the characteristics that they possess: for example, the way the irises of their eyes change shape depending on the time of day, the way their fur seems to cause sparks due to static electricity when they are petted (especially in winter), the way they sometimes lick blood, the way they can walk without making a sound, their wild nature that remains despite the gentleness they can show at times, the way they are difficult to control (unlike dogs), the sharpness of their claws and teeth, their nocturnal habits, and their speed and agility.
There are many yōkai animals other than cats in old tales that have similar attributes: the deep tenacity of snakes, the ability of foxes (kitsune) to shapeshift into women, and the brutality of tanuki in eating humans depicted in the Kachi-kachi Yama folktale from the Edo period. Cats in particular, however, have acquired a great number of tales and superstitions surrounding them, due to the unique position they occupy between nature and civilization. As cities and towns were established and humans began living farther apart from nature, cats came with them. Since cats live close to humans yet retain their wild essence and air of mystery, stories grew up around them, and gradually the image of the bakeneko was formed.
One folk belief concerning the bakeneko is that they would lick the oil of oriental lamps, and in the Edo period encyclopedia, the Wakan Sansai Zue, it is said that for a cat to lick this oil is an omen of some strange event about to occur. People in the early modern period used cheap oils from fish, like sardine oil, in the lamps, and that could explain why cats would want to lick them. Also, the diet of Japanese people at that time was based mainly on grains and vegetables, and the leftovers would be fed to the cats. However, since cats are carnivores, such a diet would have been lacking in protein and fat, and therefore they would have been even more attracted to the oil in the lamps. Furthermore, the sight of a cat standing up its hind legs to reach the lamp, with its face lit up and eyes round with anticipation, could have seemed eerie and unnatural, like a yōkai.