From Redwall MUCK Wiki

When the warrior squirrel Rinzo first arrived in Mossflower from the Northlands he realized there was yet, still violence in this new place. He realized that there might be a way to control the vermin here though. He set out to find and recruit various warriors creatures to help him create the ultimate peace in Mossflower. The B.O.W.C.I.M. or Band of Warrior Creatures in Mossflower was then formed. Any able bodied warrior has the right to join as long as they have a pure heart and a desire to defend not destroy.