Blend together the cheeses until smooth. Stir in the Worcestershire sauce, celery salt and onion salt, adding more to taste, if desired. Shape into a ball and set on a serving plate; cover and chill 2 to 3 hours or until firm.
Score cheese ball with vertical lines, if desired, to resemble a pumpkin. Toss walnuts with paprika; press into surface of cheese ball. Break a pretzel rod in half and insert in top for stem, if desired. Arrange crackers around cheese ball.