When my buddy and I went in there, there were a lot more of the regular puppets. When we opened the B room there was Brenner and at least 5 regular puppets right behind that door and coming straight at us. I hope the next time we go there it will be less overrun by puppets... Right now we are just stocking up on gear to prepare for another heavy engagement down there.
You can but it takes a lot of shots to the head. The little baby on it's back is the weak spot. This will always be a 1 shot kill with a ranged weapon (not melee weapons) Hope this helped! :)