Strigoi are the evil spirits of the deceased rising from the tombs (or living) that transform into an animal or phantomatic apparition during the night to haunt the countryside, troubling whoever it encounters. When it comes to a living becoming a strigoi, they can be humanoid living creatures with certain magical properties at their disposal. Some of the properties of the strigoi include: the ability to transform into an animal, invisibility, and the propensity to drain the vitality of victims via blood loss.
Strigoi are also known as immortal vampires. Unlike vampires, the strigoi are animalistic and primal which distinguishes them from the normal vampire race, although they can also be counted as similar to the Original Vampire. Mentally and emotionally, a Strigoi is thought to have inner clarity, having no worry or care and the inability to have mental or emotional pain, such as sadness, fear, or guilt. Their humanity is removed by their transformation and they become highly immoral. In general, Strigoi become evil and murderous, taken by animal like instinct to hunt, kill and feed, though they are able to think and speak.
A strigoi's appearance can vary, however, over time they slowly become more monstrous and hideous in terms of appearance and characteristics. But even then, one should not underestimate the power of the creatures due to their large bulk and monstrous nature, they still retain their deadly speed and power capable of matching and sometimes even exceeding the ability of any vampire. Their bloodlust is also known to be stronger than a vampire's to the point where they are even willing to drain the blood of the latter as well.