The Standard Infantry Entrenching Tool, commonly referred to as a Lobotomizer or Lobo, was a tool and melee weapon used by the United States military. It was used to dig holes and trenches but was equally effective as a close quarters weapon against zombies, making it very popular with soldiers.
The Lobotomizer was designed by the Marine Corps as they sought to produce a cost-effective weapon that could be easily produced. Since it was made of out the metal from recycled cars their was a large amount of metal available to produce them. They were designed to function as both a tool and weapon so resembles a cross between a shovel and battle-axe. Twenty-three million were produced during World War Z, with production continuing even after the war was over.
The Lobotomizer was put into action shortly after its development during the restructuring of the military. They were used mainly as tools during the Battle of Hope and were only used as weapons in the closing stages of the battle. After the battle was won soldiers armed with Lobotomizers were assigned to roll the corpses into ditches and eliminate any zombies that had managed to survive the battle. They presumably were used throughout the war and are still being produced, indicating that they are still a popular anti-zombie weapon.