Tex-Mex Burgers

1 ripe Haas avocado 1/4 cup sour cream 1 tablespoon lemon juice 1/8 teaspoon Tabasco 1-1/2 pounds lean ground beef 1/4 cup dry bread crumbs 2 tablespoons water 1 tablespoon Worcestershire sauce 1/2 teaspoon salt 1/4 teaspoon ground black pepper...