This prop will probably be in a blank section in the cave after maybe some black threads and a bug track. I'm going with black eyes. I'll try to make it as realistic as possible. I'm not shure what the body will be made of. I was thinking chicken wire but what do you think?
Dead fish prop
Do the shiny black eyes, but plant some LEDs just above or below the eyes so that they will shine no matter what angle the viewer has. They can be obscured by fur or folds in the facial structure, or even hidden on the legs or pincers so that the lights aim backwards at the eyes and "Face".