Telvetic
The Telvetic are a race of mimicking humanoid slug-like parasites that take on attractive forms and reproduce parasitically. They evolved to be physically attractive to humanoid species, once they have successfully lured a humanoid into coitus, they secrete their tiny young through the urethra or cervix, the young, being mobile, then move up to find a latching spot.
When breeding with females, they feed on their eggs and replace them, mimicking a fertile egg and forcing the body into a pregnant state, in which they grow abnormally fast and eventually erupt out of the unprepared womb.
When breeding with males, they move up through the urethera, kidneys and liver, eventually settling in the host's digestive track, growing within until they erupt out of their stomach.
Telvetics can also breed through oral sex, with the young moving down the esophagus, as they are resistant to stomach acids and digestive enzymes.
Telvetics mark their hosts with a powerful pungent odor, at first odorless, after 24 hours the material begins breaking down, releasing a foul stench that is very difficult to remove. It can be removed during the odorless stage through chemical means.
Telvetics are most commonly smuggled for use as prostitutes due to their evolutionary advantages, but this is forbidden by council law. Telvetic prostitutes are often sterilized prior to use and in the underworld there are clear brands and marks to show this. This is an expensive procedure, however, so it is advised to be wary and if one must use a Telvetic, to familiarize oneself with the marks and brands before use.