You'll first obtain the Viral Proliferator on the Recreation deck, in the Crew Quarters area. Like other Exotic Weapons, it's designed to fight off Annelids, but even so, the Proliferator is definitely not a normal sort of gun. It has two modes: Anti-Annelid, and Anti-Human, which do pretty much what they say. Additionally, rather than fire bullets, you'll need to hold down the trigger to release a projectile, and let go of it to detonate at the right time.
Overall, it's hard to pass judgement on the Viral Proliferator. It has its uses in that it can utterly destroy almost any Annelid threat in a few shots, and its unique projectiles can be guided in ways that don't directly expose you to danger. As far as downsides go, its Anti-Human mode is deadly for you if you're in range, it must be researched to get working, and Worm Clusters are an exceptionally rare type of ammo. If you've dedicated yourself to Exotic Weapons, then the Viral Proliferator is a good workhorse when dealing with Annelids... everyone else can probably leave it on the floor where it's found.
Exotic Weapons 4, Research 3 (Technetium, Tellurium), (Maintenance 4, Repair 4)
|If you've spotted piles of worms on the floor aboard the Von Braun, you've likely passed them by assuming they're mere curiosities. Not so. If you've got a Small Beaker or Large Beaker, you can use it to pick up those worms, and you'll have a Worm Cluster to power your Viral Proliferator or Annelid Launcher. Unfortunately, this is the most rare of all ammo types in the game, and you may be better served by using Molecular Duplication to keep your supplies up than hunting them down yourself. The two sizes of Worm Cluster relate only to what sized beaker has been used to pick them up; there's no difference in damage quality or type.
|Upgrade 1 - Clip Size & Damage Increase
|This modification brings the clip of the Viral Proliferator up to 18, and also provides a modest damage boost of 10%.
|Upgrade 2 - Worm Consumption & Damage Increase
|This second modfiication will make the Viral Proliferator a good deal more efficient, reducing its consumption of Worm Clusters by 50%. As per usual, you'll also gain a damage bonus of 25%.