The shadowy shadow
Bob is the group’s representative to the shadowy powers, trying to win their favour for the Shadowfell and its allies.
He is described as having no true discernible features, instead appearing as a black presence. As he only reveals himself to the group in darkness, it’s near impossible to see if there’s anything inside the darkness that is his face. Whenever he appears, his body seems to form out of shadowy corners and a disgusting cracking and popping sound can be heard (which you assume to be his bones taking form. Gross.). Oddly enough, this same sound could be heard when you once discussed his appearance with him.
In the past, Bob has also mentioned allies among the trees. This was unconfirmed as you were unable to find anyone at all among the trees. Bob is potentially a liar. You bastard Bob.