The Pentagon Thief was a scientist working in the Pentagon. He used his clearance to gain access to the Wunderwaffe materials the army had confiscated from Der Riese. Like Richtofen, he was an Illuminati agent. Using a teleporter, he traveled back in time and gathered zombies. He then tried to brainwash the zombies with Soviet mind control technology that the Pentagon had somehow gotten a hold of in an attempt to make them controllable. How he became zombified himself is unknown.
The Pentagon Thief appears somewhat as a "mad scientist" covered in a red aura of numbers. It is capable of teleporting onto the map on certain rounds, and will attempt to steal players' weapons. It approaches one target (if playing with several people), and can be killed. It is very difficult to kill it without the use of Wonder Weapons. If it succeeds in stealing a player's weapon, the player must use their secondary weapon. It will teleport around and eventually leave the map, once it has stolen a gun off of each player.
If it is killed after stealing a player's weapon, it drops a Max Ammo Power-Up and gives players their stolen weapons back. If it is not killed, the Max Ammo is placed in the electricity room. If it steals a weapon, the player whose weapon has been robbed is teleported to the science laboratories. It will occasionally leave a Fire Sale power up after its death.
If the Thief is killed before it steals any player's weapon, it then drops a Max Ammo power up and a Bonfire Sale (not to be confused with Fire Sale). The panic room with the Pack-a-Punch Machine is opened, and the machine costs only 1000 points to use. All Teleporters are also switched to lead to the Pack-a-Punch Machine.