A fatty is a one pound chub of breakfast sausage that is filled with any filling that you desire from  breakfast fatty to a pizza or a Philly cheese steak. They are generally wrapped with sliced bacon in a weave pattern and smoked at 250* for 2 to 2.5 hours. Variations would be different meats, beef, turkey, or lamb. sometimes they are not wrapped in bacon or they are wrapped in turkey bacon.