Black Cat

"Welcome, Helen. My faithful witch."

- The Black Cat

The Black Cat (黒猫 Kuroneko), also simply called the Demon (妖怪 Yōkai) is a formless demonic entity that possesses corpses to interact with humans. The demonic familiar to the witch Helen Thosel, the black cat can form contracts with humans, turning them into demons and granting them immense magical powers; the cost, however, is the delivery of souls.

Trivia

 * The black cat, like Helen, is based on the Black Cat from The Witch's House, and shares a similar relationship to Helen.