A species of sentient slime that inhabits and wears the skins of previously consumed victims. Outside of its host's skin, the slime is clear purple in colour. While wearing a human skin, the slime will, to all intents and purposes, appear to be human aside from the eyes. These are the same purple colour as the rest of the slime. Purple slimes appear to have a preference for female skins. After taking a new skin they will often modify the contours of the body—increase bust size, decrease stomach size—in order to increase the sexual attractiveness of their new form.
The purple slimes are incapable of repairing their stolen skins. Any tears or punctures will cause the inner slime to ooze out and plug the wound, much like amber. This is the limit of their healing capabilities. Eventually their host skin will degrade to the point where the purple slime will need to discard it and seek out a fresh skin.
Rather gruesomely, the purple slimes form sentimental attractions to the skins they take. They adorn their dwellings with the skins left behind from their feeding. Previously-worn skins are afforded a higher status, sometimes even bordering on a strange kind of reverence.
Suffice to say, this can be highly disconcerting and distressing for any human visitor. Our negotiators and ambassadors will require an appropriate amount of forewarning.
The purple slime incapacitates victims by extruding slime tendrils into the victim's body. These invade through facial orifices such as the nose and mouth, and travel to the brain, where the slime is able to induce unconsciousness with no additional side effects other than slight short-term memory loss. While wearing a skin, the slime will use this as a disguise to get close enough to their target. If the slime has no skin they will instead attempt to creep up on sleeping or similarly indisposed targets.
They feed by extruding their amorphous body into their prey and slowly digesting them from the inside until nothing remains but the outer skin, which the slime either takes as a trophy or new skin to wear. While unpleasant, I can at least understand this from a biological perspective. What makes far less sense is that the purple slime will sexually stimulate their victim, so that they are in a near-constant state of sexual climax even while being consumed from the inside.
Why? We observe this time and time again. Why is inducing sexual arousal so important to so many HSIOs? It just doesn't make any evolutionary sense.
Purple slimes are very fragile, especially in comparison to other slime-type HSIOs. Without a host skin they have difficulty in holding their semi-liquid forms together and are especially vulnerable to both mechanical and chemical disruption. While in a host skin they are no stronger than a typical human and might even be weaker. Their skins are just as easily lacerated or punctured as human skin, and cannot take too much damage before becoming unusable to the slime. However, one should always be aware of one key difference between skin-wearing purple slimes and human combatants—the slime has no vital internal organs and is unlikely to be stopped by a single bullet to the head or thorax. Use sustained fire to shred their stolen skin.
Their mimicry of humans is effective, but always given away by their eyes. Thankfully, this places a hard limitation on their infiltration capabilities as it is so easy to detect whether a slime is trying to masquerade as human. We should still be vigilant and guard against any infiltration attempts.
They are extremely fragile once their disguise is seen through.
I wonder if this weakness is the reason why some of their colonies have approached us with offers of peace, friendship and co-operation. Command is receptive to the idea. Vampyrotiea and similar HSIO individuals have proven invaluable to our understanding of H-space. It will certainly raise challenges. How can we possibly co-exist with an organism that consumes us and wears our skins?