Who is Mr. Wormwood from Matilda and what is their importance?

Mr. Wormwood is Matilda's father. He is a second-hand car dealer, and he has no moral dilemmas about taking advantage of his customers. He doesn't simply mislead them or leave out important, relevant information. He tells bold-face lies to his customers and has various techniques to back up these lies. As a father, he is not concerned about these tricks from his children. Instead, he comes home and brags to his son Michael about the success of his lies and about how much money he has made.