Zombie Scientists are a type of Zombie set to appear in the upcoming map Waffenentwicklung. They apparently steal your Pack-a-Punched weapon, keep it for about 5 seconds, then toss it back to you. Your weapon will now not be upgraded anymore, as now you must go back to the Pack-a-Punch Machine and pay another 5000 points to upgrade it again. However, if you have another weapon, you CAN kill the Zombie Scientist while he is removing the upgrade on your gun. It will take 4 hits with a knife though, so if you have no ammo in another gun, you're out of luck.