What cruel action does Heathcliff take to warn Isabella not to marry him?

Question

From chapters 10-17 in Wuthering Heights by Emily Bronte

Answer 1

He hangs Isabella's dog.

From chapter 14:

"But I don’t care who knows that the passion was wholly on one side: and I never told her a lie about it. She cannot accuse me of showing one bit of deceitful softness. The first thing she saw me do, on coming out of the Grange, was to hang up her little dog; and when she pleaded for it, the first words I uttered were a wish that I had the hanging of every being belonging to her, except one: possibly she took that exception for herself."