Who is Dr. Krokowski from The Magic Mountain and what is their importance?

Dr. Krokowski is Dr. Behren's assistant. He is a short and stocky man with a beard and a hearty manner. He conducts psychoanalysis sessions on patients. Krokowski also offers regular Sunday lectures on the relationship between love and death, one of the book's major themes. Hans Castorp begins to see him for psychoanalysis sessions after he falls in love with Clavdia Chauchat.