Basil the Death Ram

From some unknown source, these deadly sheep roam the verdant hillsides where they live, ravaging anything in their paths. From a distance, they seem to be nothing more than wild, somewhat dirty sheep. Up close, however, the sheep can be seen to have an evil nature. Their large mouths are filled with long, sharp black teeth that drip vile ichor. These sheep attack any living thing that they can find, fearing nothing and fighting to the death. Because of their ferociousness. 

Death sheep, carry a deadly and supernatural disease, are carnivorous beasts recklessly attacking any creature standing in it's way. Death sheep usually travel in groups of 2-20, only stopping to eat the flesh of their prey.

Any living creature bitten by the death sheep that failed the saving throw will become as mad as the sheep are in 1-10 days and will see symptoms appear within hours, and fall dead within days unless cured. The creature must be cured within 1d10 + [Constitution modifier] days, suffer the maddening effects of the disease. The victims teeth gradually turn black and become sharp and pointed, and finally the victim is totally consumed with insanity and berserkly attacks any living thing that it senses, using only its teeth.  Any creature consumed by the disease cannot be tamed or controlled in any fashion. Such creatures can be captured and penned up, or perhaps tied up and released later.

(A favorite battle tactic of one general was to capture several of these sheep, place them in boxed carts, and release them in the direction of his enemies. It worked well until one sheep turned around and looked back; then things got a little sticky).

All maddened and surviving victims of the death sheep, except other sheep, live only as many days as they have hit points. Therefore, only the death sheep are ever found, and they do not attack one another. Death sheep typically travel in flocks (woe to the unwary wolf!) and eat animal flesh, be it fresh or rotten. Birds, reptiles, and all other animals (except mammals) are immune to the poisonous bite of the death sheep. It is speculated that the death sheep are a product of some mages experiments with rabies, and rumors hold that one particularly ambitious death sheep named Basil is their leader.

The spells Protection From Poison, Lesser Restoration and Remove Curse before half of the 1-10 day cycle is complete. Any of the above three spells cast singly only slows down the progress of the disease by one day., or alternatively the creature can drink either a Potion of Vitality or an Elixir of Health.

Symptoms include blackened gums with seeping dark foul-smelling liquid, swelled mouth, rapidly spreading black rash, pain, fever, hallucinations and insomnia.