Who is Layzar the Butcher from Tevye the Dairyman and the Railroad Stories and what is their importance?

Layzar is a wealthy widower and baker, who wishes to marry Tevye's eldest daughter. He is described as a coarse man, who during the marriage negotiations acts as if he is shopping for cattle. Tevye initially accepts Layzar's suit, but later rejects it as his daughter has other plans..... she is secretly engaged to Motl the tailor.