Rat Pack

Identified in Raising Steam, this is a specific named group under the aegis of the Ankh-Morpork Scouting (and possibly Urban Survival) Federation. Principally composed of Dwarfs, there are several fully accepted troll members. Magnus Magnusson, a Dwarf who runs into trouble in Bonk, is a member. As incidental information we are told that there is a membership badge which is worn on the back of a (reversed) helmet.