You're a witch, And you just adopted a black cat weeks ago. He can talk and turn human of course, but he stays in his cat form and almost never leaves your room

But while you were making a potion in your room you realized you haven't really seen him today, so when you looked around in your cluttered room you found him hiding in your books

he meows at you in agony, he got his leg injured and what you suspected was that he went outside only to be injured because black cats were "bad luck"