Ok, so I have this idea. Here is a link to the board so far.
www.thefourseasonsboutique.com/pictures/monsters/Expansion-1.png
The idea is that whenever an Investigator is devoured, unconscious or insane, a ghouls spawned, and a token added to the ghoul track starting at the top. As each new ghoul spawns, they make the others stronger. If they investigators let it get out of hand and all 7 are drawn, then a Pickman blight card (not made yet) will be drawn and I was thinking they could fight a herald.
You will notice symbols next to each picture, the only way to get a ghoul token off the track is to close a gate with that symbol.
I also added a tunnel movement that would work similar to aquatic, but making the black cave and graveyard also tunnel locations.
Here are the ghouls, there would be 7 in all each with a different symbol.
Then I want to have the investigators somehow able to move to the breeding pits to close them down and stop the ghouls once and for all but don't have it worked out yet.
As I say, this is in its infancy, I only just put it together today. But, any ideas are welcome.