Starfinder: Linked
This particular breed of blood-drinking undead appears s to be more like ghouls than vampires. They are generally fairly small and look almost skeletal. The bodies are always hunched and they never stand up straight. The flesh is onyx-black, and the eyes are even blacker, which oddly enough stands against the black flesh. They are utterly hairless and do not wear clothing. The creature’s teeth have become twisted and rotted, almost like that of a long-time drug addict, but can they can still deliver a deadly bite.
These creatures are also shockingly weak. They cannot batter through barricades, nor can they do much physical damage when they do engage in combat. What they lack in physical strength, they make up in agility and predatory cunning. One would think as weak as they are physically they would be easily defeated, but this is not the case. The Linked regenerate so fast they can shake off the worst damage and continue to fight.
And the fact that their bite is highly infectious and the change will occur shockingly fast.
When these beasts bite a victim, they will have two possible effects to choose from. First the bite can infect the victim with the same virus that re-writes their genetic code and turns them into one of these beasts. The second effect is to put the victim into a coma-like state, allowing the creatures to take them back to their lairs to be used in a type of blood-farm, allowing the members of the pack to feed off the victim almost indefinitely.
In combat, these creatures are uncanny. They use tactics. They will even sacrifice newer members of the pack as a distraction in order to sneak up from behind or to take advantage of flanking or other similar situations. They will also continue to fight, no matter the odds, even to the very last member of a pack.
When they are damaged in combat, they will automatically regenerate. The only damage they cannot regenerate from is fire or acid. If they come into contact with silver or Ultraviolet radiation, they are instantly killed by the touch. When this happens, the bodies turn to ash, leaving behind the skeletons.