Packmasters and Master Moulders lead units of Giant Rats or Rat Ogres. They cannot leave their unit or join another. Missile hits and Impact Hits against these units are randomised as follows: roll a D6: on a 1-4 a Giant Rat or Rat Ogre is hit, on a 5-6 a Packmaster is hit. If there is a Master Moulder or any differently equipped beasts, then hits must be further randomised to determine exactly which model is hit.