Nekomata

According to Japanese folklore, a cat (neko) that has lived for a long time can become a kind of youkai called a nekomata. It was believed that after a cat reached ten years of age, its tail would slowly split into two tails, and, along the way, it would develop magic powers, primarily those of necromancy and shamanism. Nekomata also have an ability to shape shift into a human form and are generally hostile to humans.

There is also one kind of Nekomata that lived in Nabeshimahan, which lived long enough to split its tail six times, resulting in seven tails. It is the most powerful nekomata in Japan.