The latest Zombies map to be added to Call of Duty: Black Ops Cold War is called ‘Mauer der Toten,’ meaning “Wall of the Dead.” This map sees the members of peacekeeping force Requiem forced to build a warhead to close the Dark Aether portal that was opened in Berlin by traitorous scientist Aleksandra Valentina. We played several co-op games on ‘Mauer der Toten,’ and we even found out how to unlock the robot, Klaus.

Source: N4G PC How to Unlock the Robot in the 'Mauer der Toten' Zombies Map of COD: Black Ops Cold War