One card with a Yellow border has 3 listings - R'lyeh, Yuggoth and Other. In the Other Section it reads: "The cultists thrust you forward and the God of the Bloddy Tongue surprises you. You gains a +1 to all skill checks against this monster for each Uniques Item or Exhibit Item you have." If you Ancient One does not have the Masks in play do you have to pick out the God of the Bloody Tongue from the Mask creatures and confront him for the first round since he surprises you? If not, how is this particular card handled?

Yes,you encounter God of the Bloody Tongue regardless of whether Nyarlothotep is the AO in your current game.