A large backpack is a container item worn on the back.
The large backpack and military backpack outclass every other backpack in weight reduction and carry capacity. If the player has the organized trait, the backpack has a capacity of 39.
The large backpack can be found on reanimated survivor zombies with supplies inside the backpack. Survivor zombies can be seen in barricaded houses and among hordes. The military backpack can be found on National Guard zombies.