This is a very cute Halloween book by Emily Horn which features a homeless black cat seeking a home.
He reads in a book at the library (his home essentially) about witches who love black cats. So he sets out to find a witch. He learns their characteristics (wear striped stockings, carry brooms, cook with cauldrons, and have pointy hats) and seeks out people with such.
Disappointed in not finding any witches on the streets, he returns to the library where a group of witch-schoolgirls happen to be visiting. He is adopted by them and taken to their school as the resident black cat.
Cute story. Great illustrations. I like it because it makes the library a cool place (cats hang out there) where reading books are featured and the cat finds a loving home. Short, quick read to go with the season.