Bitterhound

I can't take all the credit for this one; many of these ideas were sourced from Anonymous contributors.

Bitterhound – 1d8+1 Magic Hammer

This is a magic hammer appearing as the head of a dog. It is wrought in a dark iron and it's unusual shape has not inhibited its killing potential. If this hammer strikes a foe and the wielder lets go of the hammer OR if they are killed/knocked out that round and lose grip of the hammer, the “mouth” of the hammer opens and has bitten the target instead. It still deals the regular damage of the attack, but the hammer has now got its jaws on the target.

The dog's mouth grips into flesh very hard, and on certain body parts, may bite down to the bone. Any attempt to chisel or pull off the hammer will result in it just biting down harder, with all the unending pressure of metal. In this form, the hammer emits a subtle curse onto the wearer.

Wild animals that are hunted in part by dogs (bears, boars, wolves, rabbits, foxes, etc.) now despise the one who the hammer has bitten into. They always roll the worst possible reaction checks, or run into one group of 1d4 of any of these types of animals once per day when traveling through the wilderness. Within a city or town, the animals are kept mostly at bay, but when traveling the roads they will always stalk and try to attack the person right as soon as they are alone or setting up camp. Animals that are too small to pose a serious threat instead attempt to steal or damage vital party equipment, or even lead the bitten one off a cliff or into a more dangerous monster with a fake chase.

This power is only active while the “dog” is biting the person. If the hammer's head is broken off from its handle, the head continues to bite and the effect continues. The Bitterhound's curse is ended by casting a remove curse spell, or upon death where it releases its jaws and serve a new master.