Had zombies "Running" from me, more like a shambling turn away but they did not get far. Skeletons as well, running in fear. These are what are known as Mindless undead, without fear or strategy except to kill you the living. Would they get Morale checks? Seems inappropriate considering the lack of logical thought or even the desire to self preserve. Ghouls I could see having checks as they have a sort of animalistic mentality, but the animated dead, such as Zombies and skeletons, why would they run for their... Lives?
~LawfulJoe