He is described as sensitive, emotional, intelligent, prone to anger and violence, and very good at speaking. He learns how to speak from a family that he observes. He teaches himself how to read the books that he found. He has a severe sense of rejection from Victor and from every human he encounters. He has bad experiences with people. That makes him feel as though he is hated and unwanted. He resents humans and even feels hateful towards them because of how he has been treated. As a response, he kills several people, including Victor's younger brother William, Victor's best friend Henry Clerval, and later Victor's wife Elizabeth Lavenza.