Codex: Cunt-Slug

These parasites feed exclusively on the semen of other creatures. To obtain it, they hibernate in mud, and awaken when they smell that a large, female mammal is nearby. They then compete for the right to claim the mammal's womb as their home, usually by whichever can get there first.

When the parasite is hungry, it emits a chemical which makes its host irrationally horny, and causes her to emit pheromones which draw compatible males from miles around.

When well fed, the parasite releases its spawn within the host's womb. These grow quickly and also demand large amounts of semen. They grow to maturity in approximately two weeks and leave through the birth canal, either to find some mud to hibernate in, or to immediately infest a nearby creature.

As the parasite feeds on all of the semen entering a host, they cannot get pregnant. This makes them a big problem for wild herd animals, as a single member of the herd being infested will result in them birthing more cunt-slugs, which will go on to infest the rest of the herd, stopping all breeding dead.

In intelligent creatures, they are a lesser problem, as males are not mere slaves to their instincts. It is quite obvious that an infested woman is not in her right mind, and removal of the parasite is fairly easy. Assuming, of course, that the male is not inclined to take advantage of her anyway.

Women infested with a hungry cunt-slug are easily manipulated, with the mere promise of sex usually being enough to make them do whatever they are told.