Animated Dead

The Animated Dead are essentially just corpses without minds or souls. They are used as puppets by mages who wield Necromancy. Animated Dead will simply follow their last instruction until they are destroyed, if they are prevented from being able to carry out their task, they will attack or attempt to destroy whatever or whoever is preventing them from completing their task.
Zombies, Mummies and Skeletons are all animated dead, just with different levels of decay or preservation.