I'm not sure if anyone has read Green Tea by Joseph Sheridan Le Fanu, but I'm sure many have. If not, I highly recommend it. Anyway, I am trying to formulate a lurker based on the apparition, and I was stuck for a name...
Although apparition might be a good one. Basically, he is a diminutive monkey-like creature with glowing eyes. He haunts one of the main chcracters in the story incessantly. Sometimes disappearing in the unknown only to return again, furious. Yet he can't touch or harm his victim, only occupy their field of vision... eventually leading to madness.
I think he would be interestring to have in a game as an option for the Lurkers player to "haunt" an opposing team-member. It is not a lurker that you actually control, but more like a spell effect.
The apparition may cause negative modifiers to abilities, and over the long term affect the characters sanity.
And it would be fun to use many of the various familiar miniatures out there.
Is this already in source material that I've missed?