Ghouls - what are they?

These will be the main low level antagonists for the players in my upcoming Hunter: the Vigil game. However their exact nature remains elusive and is something I would really like to tie down. They are represented in medieval folklore already and this depicts them in a number of ways. The most common being the fact that they eat human flesh and that they live in graveyards. They are more often linked with Werewolves or at least exhibit similar traits than they are with Vampires. They are often described in Arabian sources as shape shifters though they generally change into Hyenas rather than Wolves. They are also reported to prey specifically on young children, to rob graves and to drink blood. One of the most interesting traits is the ability to take on the form of a victim they have previously eaten. The definition from White Wolf is:

Slaves to the addictive taste of vampiric Vitae, ghouls trade servitude for that heady substance. Servitude, however, damns them far more than they know, as their unnatural craving drives them to ever greater desperation and depravity. Among those known as blood slaves, there's no such thing as "just one fix."

However this doesn't fit exactly with what I have in mind. It is close but not exact. I would prefer to have the Ghouls act as the minions of a powerful witch rather than a vampire. I suppose a thaumaturgical vampire wouldn't be out of the question.

The Purpose:
The Ghouls are in the game to introduce the players to the World of Darkness. They will be the cause of whatever incident is the first that the players come across. They will then be used to reveal that they are not alone in this World of Darkness but only pawns in a struggle. They will also provide a direct physical threat to the Hunters and will actively seek them out. The fact that they are almost indistinguishable from the normal populace will foster a sense of general uneasiness as the Hunters won' know who to trust.These will give the players that first sense that they have dealt with a problem and succeeded. Some hunting packs of ghouls will be easily dealt with and then there can be some for of a boss monster, maybe that can be a vampire. It could also be a better than average ghoul, I haven't decided. He (it?) can be hidden somewhere within their base of operations meaning that the party have to go in a deal with it.

The Hide-Out:
This is simple. The Ghould need flesh. Human flesh to be exact. Where is this easily available? A crematorium would be good. Who inspects the ashes to really see if they are human ashes and not something else. Combine this with a hospital and a large graveyard and you pretty much have the perfect setting for a Ghoul Clan. It also allows for a gunfight without too much worry that the police will arrive. A graveyard at night won't be filled with people afterall!

What they are doing:
Now here is always a difficult question. Survival is not really an option. If they are merely surviving then they are not going to be noticed by anyone. They can't be just minding their own business. So they need an adversary. I don't want to detail that just yet but the Ghouls must be acting against them. So what exactly are they doing? Killing homeless people might be a trope of the genre but it works. That is why it is a trope! So someone or something is controlling the homeless people. These are then being used against the Ghouls. Why? Hmmm well drawing on the Algol inspiration the Ghouls are in possession of some powerful Taliman and this other power wants it. Infact the talisman has just arrived in the city or is on its way. A play is being made for it which means the Ghouls are under surveilance. So they have reacted and are attempting to remove the people that are being used.

I now have one basic group in the web of intrigue that still needs some development. A good start is half the work after all!