The first strigoi were created by spellcasters who subjected swarms of stirges to transmutation spells. Other strigoi have emerged as the results of similar spellcraft, as the byproducts of outlandish scientific experiments, and from stirges draining well-fed vampires. When a strigoi arises, the unnatural creature is overwhelmed by instinctual hunger that drives it to undertake bloodthirsty rampages along with swarms of emboldened, bloodsucking pests.

Strigoi drain the blood, marrow, and soft tissues from their victims, leaving behind nothing but empty husks. Due to the horrifying nature of their deaths, those slain by strigoi occasionally reanimate as boneless.

Many strigoi seek ways to return to their former existence while being compelled to drain living victims. Others, though, embrace their new forms and mimic vampires. These would-be bloodsucker aristocrats create stirge courts amid scabrous husk-decorated villas and drain the life from any who balk at their grotesque gentility.