Owlbears are notoriously bloodthirsty killers, well known for their short tempers, aggression, and savage nature. They tend to attack without provocation, slaughtering any living creatures that cross their paths. Many scholars that have encountered these creatures in the wild have noted that they all have red-rimmed eyes that roll about wildly when they close in for an attack. This is sometimes presented as a sign of madness, suggesting that all owlbears are born with a pathological need to fight and kill, but more level-headed researchers believe that it's simply part of the way the massive bird-beast's keen eyes are constructed.