Packmules are the backbone of any individual or company who wants to transport a significant number of goods across a distance, especially in places where a horse and cart cannot traverse due to either rough terrain or narrow passages.
In Dungeon Siege I and Dungeon Siege II, Packmules can be bought from traders and breeders across the continent. What they lack in fighting skills is largely made up for in their boosted inventory space - three times the loot that a humanoid can carry.
Packmules are not defenseless though, their kick is enough to seriously damage weaker enemies and cause minor wounds to stronger foes. They have no qualms about rushing in headstrong to defend their masters, braying and kicking fiercely.
The level, health and attack of a Packmule is entirely dependent on the party it is attached to, regardless of where they are acquired from. Packmules will set their health to be roughly two thirds of each party member and their attack will be set at roughly three quarters. Unlike humanoid characters who have a fixed level regardless of the party, Packmules will change their stats every time they are acquired, even after disbandment.
As Dungeon Siege I only allows for individual characters in multiplayer, Packmules cannot be acquired outside of modding. However, Dungeon Siege II multiplayer subsequently allowed individual players to control more than one character, renewing the allowance for Packmules provided there is at least one humanoid character in play.
Due to the change in party setups in Dungeon Siege III, Packmules were not featured.