The LZ-52 Limbo is the new weapon in Carrier. It basically fires a horizontal laser (like in this achievement's picture). You get it from the 3d-Printer. This costs 1000 points each time, or 10 points when a power surge is picked up. The 3dprinter/box always spawns in the armory first, after that, it's random. Possible locations besides the armory are
- the moon pool, on the opposite side of exo health
-The gun deck
- In between the other spawn location and the armory
-med deck
Once you get the limbo, make a train of zombies, and shoot the limbo at the train, and hope it will hit 18+ enemies. Be sure to aim at their chests, for more damage compared to the legs. This is of course easier in higher rounds where there is more zombies. You just have to hit them, not kill them.