Thunder
Madame Morrible liked thunder. It was the signal of an approaching storm.
Thunder could scare people, especially young children. And Morrible wasn't very fond of children.
It always followed lightning, and that made it seem even scarier. For Morrible knew how to manipulate emotions quite well.
But she liked thunder most because it electrified the air, left people wondering whether it was the Wicked Witch's doing.
And she never let them know the storm was hers…