A member of the 'Humans Against Monsters' group.
You can pickpocket these for all sorts of odd items. An incomplete list: Leather Body, 5-16gp, steel dagger, gloves, H.a.m. Logo, bronze axe, iron axe, steel axe, cowhide. iron ore, buttons, tinderbox, logs, raw chicken, Ham Robes (top), Ham Robes (bottom), boots, Ham hood, rusty sword, Level 1 clues, uncut opal, uncut jade, damaged armor, coal, and Slayer staff. If you fail to pick pocket a H.A.M member three times you will end up in a random place usually near the H.A.M entrance, or in the H.A.M jail.