Impregnader is a weapon probably invented by Dr. Proton during the 2nd wave of alien invasion on Earth that takes places in the DLC. It is basically a living Pregnator leashed within some machinery that makes the user able to control his "spittings". When not shooting, the ammo will constantly rise to maximum as the tied alien produces more and more sperm all the time.
It shoots green balls of goo that travel in a parabolic trajectory and inflict splash damage. Standing too close to the target will also hurt the shooter, but the splash radius is far smaller than that of explosive weapons. It is good on close to medium distances and offers more advantage when the user is located on higher level than his target.