They are always made of nat like creatures that drip a sticky slime. Ranging from 20' to 50' square in size by HD they still so the same damage to individuals. Only a cleric of 34th level or above can remove it at normal cure disease chances. Decay Hordes can only be hit with magical weapons or spells and are immune to cold, lightning, disease, mind control, and sleep spells. 80 yards They can only summon small dragons.
Larger ones are able to dismiss the call.
The breath weapon is diseased with lycanthropy. The method of transmitting the disease explains why the numbers of this creature are continuously decreasing, not many can survive such an attack to have the chance to become a lycanthrope. The dragon's bite and claws do not cause the disease. They are much like zombies, roaming to destroy life. Because they are undead, they cause significantly more damage when they hit.