Savager

A porcupine-quilled creature built like a grizzly bear with claws and fangs like scimitars. A savager’s forelegs are mangled and scabbed, and its eyes shine with hatred and anticipation.
Driven by Dark Spirits. While druids claim these bear-like animals are not cursed or enchanted, the savager’s habit of killing any living creature on sight is not natural behavior. Hunger doesn’t explain their attacks, since savagers eat only part of their kills before abandoning the meal and looking for other animals to attack. Some dark forest spirit drives them.
Gnaws Itself. When there are no other creatures nearby to attack, a savager gnaws on its own forelimbs, resulting in scabs, scars, and calluses so thick and numb that they protect the savager from even the sharpest of swords.
Rare Meetings. The only creature a savager won’t attack on sight is another savager. If they are of the same sex, the two avoid each out of self-preservation, and if they’re of the opposite sex, they mate so ferociously that both creatures are left wounded, angry, and hungry. A savager litter contains anywhere from 10 to 25 cubs, all of them born able to walk and fend for themselves. This is important, because within 24 hours after giving birth, a savager mother no longer recognizes her own offspring, and she will attack and cannibalize any that don’t escape on their own.
A savager weighs 1,800 pounds and is 11 feet long.