Who is Mr. Mallek from King of the Screwups and what is their importance?

Mr. Mallek is the high school principal, as well as a physics teacher. Over the course of the novel, Mr. Mallek and Liam have a few run-ins, but Mr. Mallek tells Liam that he will work with him if Liam works with Mr. Mallek. Liam, however, will not receive a free ride. By the end of the novel, Mallek agrees to allows Liam to finish high school at Pineville High School.