The Fang is a large group of criminals who will take any job if it fills their pockets with gold and expands their business enterprise. They can often be identified by the red pauldron (or shoulder area) each of them wears.
There are four leaders of the Fang: Ripley, Brock, Krista and Trent.
Each adds something distinct to the organization but Ripley seems to be a more clear choice for the actual leader.
The Fang was formed at some point in the last year or two and have quickly grown into a large and sometimes uncontrollable force of chaos.