The location of where the Enraged Shrieker spawns is neg 90.56, neg 19.05, neg 56.88. It is by a rock on the wall where 3 shriekers spawn and the placeholder is the left shrieker.
when u enter the deep zone go straight down the first tunnel turn right next and then go down that and turn left and 3 shriekers spawn to your left and the one on the far left is the placeholder I believe cause I killed 2 enraged shriekers in that spot.. if you go to the end of that little tunnel u get to the deranged underbulk spawn spot and its a good spot to camp right there to pull mobs and fight deranged for loot