A person that is regarded as predatory, rapacious, and fierce. They normally stick to themselves but, if threatened or someone starts a fight with them in school for example. They won't hold back and will probably hurt you. They are normally gruff on the outside but can be overcome if you are nice enough to them. Usually very very strong. There are a few per school or office.
See that guy who just transfered here? They call him The Wolf of Mibu.