@Melansjf apart from y'know all the parallels MC himself has been drawing, not to mention this very chapter where he gets mistaken for him because he was wearing a hood
@SightWarden only problem with that theory is that the pair at the mountain who told them to go left started talking about the crab walk with the chains, so they have gone the correct way.
@Sumgui it's obviously not an actual monkey. It's either some kind of supernatural creature or someone pretending to be one. I might be wrong, but I don't think the author has ever tried to portray it as just a regular monkey