Bloodbeast

This creature is greatly feared by adventurers as a natural berserker. A bloodbeast looks like a dog-faced gorilla that stands on two legs, and has one of the worst dispositions in the animal kingdom. A bloodbeast has a natural Magic Resistance of 5 and the unusual ability to Sense Emotions, particularly bloodlust and anger.
It can sense hostile emotions up to a mile away. This acts as a beacon for the bloodbeast, attracting it and triggering its own bloodthirsty behavior. By the time it finds the party, it will be in a berserk rage. It first attacks whoever has been broadcasting the anger or bloodlust, then turns on the rest of the group.
They inhabit mountainous regions, forests and swamps, though some have been found in the ruins of long-dead cities. They are solitary and active any time they sense a bloodthirsty soul. Any sort of mind shield will protect from its sensing ability, though. The GM’s decision on a PC’s (or NPC’s) bloodthirsty behavior is final.
The bloodbeast favors claw attacks, but will also attack in close combat with their teeth. They are capable of grappling, and will either hite or choke when they do