A long time ago, back in the far off time of 2000, the OGL was released. Back on the OGL and OGF list there were many discussions over what is and what couldn't be considered PI (Product Identity).
What was intended was it a way for publishers to protect their IP (Intellectual Property) while still releasing other material into the OGC pool. Among the "top tier" publishers this worked out well. Sword and Sorcerery Studios, Mongoose, Necromancer and so on all played nice and thing more or less worked out. Typically they protected "fluff" and text writeups while stat blocks were open.
Occasionally you would get someone that would try to claim some material they scraped off the net as PI (say the names of devils and demons) or the history of some historical figure, but for the most parts these were ignored when they were frowned apon. The telling thing I think is the ones that did it well are still here to tell us about it.
Well...some people still don't quite have a grasp on this yet.
Check out this post from Kobold Quarterly, on the Strigoi.
It is a good write-up for Pathfinder and I detect a bit of "4th Edition Envy" in some of the text.
What I don't like is the little bit at the end of each page where it says "(This post is Product Identity.)"
I don't think that is very neighborly of them, and others tend to agree.
In truth they can't make "strigoi" PI anymore than they could make it copyrighted. The post can certainly be PI. Their unique expression of a strigoi in Pathfinder can be PI. The name cannot.
Plus, and not to put too fine a point on it, they can't make a claim of PI without the rest of the license as stated in the license itself.
Obviously the author wants to keep his creation for appearing in other publications and that is cool, I respect that. There are better ways to go about it and his PI declaration doesn't quite pass the "reasonable person test".
In any case here is my contribution. I am declaring the following monster stat-block, write-up and all text below and including the name of the monster to be Open Content.
My OGL documentation is here, http://timbrannan.blogspot.com/p/open-game-license.html and this post is copyright Copyright © 2011 Timothy S. Brannan.
Armor Class: 4 
Hit Dice: 5d8+4** (28 hp)
No. of Attacks: 2 claws, 1bite
Damage: 1d6+2, 1d6+2 / 1d4+1
Special: Blood drain, transform into a large bird, undead
Movement:: 40 ft., Fly 60 ft
No. Appearing: 1
Saves As: Fighter 7
The much feared Strigoi is an undead form of a particularly evil witch. They are most common among the witches of the Classical and Family (Gypsy) traditions and many are part of the Mara covens. They ways to become a Strigoi are varied, but it is believed to be part of a curse. The Strigoi loses her ability to cast spells, but it is offset with her increased strength and speed (treat as 18 in both strength and dexterity).
The Strigoi leaves her grave at night, usually an unhallowed one, to feed on blood much in the same manner as a vampire. She can transform into a large, evil looking bird; something akin to a giant crow with sharp teeth in her beak.
In human form the Strigoi can appear much as she did in life. Most Strigoi have red hair and blue eyes, though scholars debate on whether there traits were present before the witch was cursed. Most Strigoi do not attempt to hide what they are and retain the palor and look of death. Grave dirt clings to their clothes and their faces are smeared with gore.
Strigoi are predisposed to return to their loved ones in an attempt to reenter their lives. This often leads to the Strigoi destroying her former family.
Weaknesses of the Strigoi
The Strigoi cannot enter a home unless invited in first. A Stigoi also cannot pass a line of grain or salt laid out in front of them. Garlic is also effective, as is silver, but mirrors are not.
Strigoi can only be hit with silver or magical items.
Like all undead Strigoi take damage from holy water and avoid holy items. They do not care for light (or Light spells), but they are not destroyed by the sun as are vampires.
To permanently kill a Strigoi one must hammer an iron stake or nail through their head into their coffin. Their heart and blood sac (a new organ that looks like a second heart but is more akin to a stomach) must be cut out and burned.
Strigoi are turned as are Wraiths.
A type of witch known as a Strigoaică or a Strigoi Viu is a type of living Strigoi. She appears as a normal human witch with red hair and blue eyes. They are immune to the attacks of other undead, but will become a Strigoi on their own deaths. It is rumored that these Strigoi retain their spellcasting abilities after their transformation.
"Strigoi" Copyright © 2011 Timothy S. Brannan
Released under the OGL as Open Gaming Content