The Witches of Worm
Written by Zilpha Keatley Snyder
Cats. Jessica's never liked them. Especially not a skinny, ugly kitten that looks like a worm. Worm. Jessica wishes she'd never brought Worm home with her, because now he's making her do terrible things. She's sure she isn't imagining the evil voice coming from the cat, telling her to play mean tricks on people. But how can she explain what's happening?