"a fat otkupshchik"

The word otkupshchik means 'lease holder'; they held government monopolies allowing them to sell restricted goods such as alcohol, or, as is probable in this case, act as tax farmers.

Private citizens would be assigned responsibility for collecting taxes, for which they would receive a cut of the money collected. Tax farmers were often seen as corrupt or at least treated with similar contempt to that which parking wardens receive in modern society. Tolstoy hated them particularly as he saw the class of wealthy merchants, otkupshchiks and others as a threat to the power of the aristocracy, and to the natural order of Russian society.