It is said that a pet cat takes the form of an old woman when it becomes older.
Its tail is split into two and it turns into a goblin called "Nekomata." It is also believed that Nekomata can talk like a human being, causes various strange phenomena and often does evil.
People are especially afraid of it as it kills and then eats people.
In addition, they say a pet cat/dog is often possessed by the spirit of dead master.
It takes revenge on people its master hated when he lived.

Kubitsuri-Tanuki
It is said that a racoon dog(=tanuki) can disguise itself as well as a fox.
It is famous for playing harmless tricks on people.
However, there is a terrible racoon dog called "Kubitsuri-Tanuki".
"Kubitsuri-Tanuki" ties a rope to a tree and lures people into committing suicide by hanging.