Mauler's Arm is an enchanted mace +2. This weapon has almost the same proterties as a Mace +2, as they both inflict the same amount damage, have the same THAC0, speed factor and weight, but this weapon raises Strength to 18 and there is no Strength requirement.
Jurrg the Mauler was the proud chieftain of a northern tribe, but feared he would be the last of his family to lead. His son Kullen was sickly, and clearly couldn't meet the traditional requirements of strength for a chieftain. Jurrg knew that wise leadership took more than brawn, however, so he bargained to enchant this mace such that it would cover Kullen's weakness. Who Jurrg made the deal with is unknown, but the cost was apparently high. Kullen came to rule soon after.