The head of this massive warhammer is made of living rock.

A galeb duhr hammer acts as a +1 warhammer. In addition, if you have the stonecunning racial ability, the hammer gains an extra ability. Whenever you score a critical hit with a galeb duhr hammer against a creature standing on the ground, the surface your target is standing on attempts to hold the creature in place. For 5 rounds, the victim’s speed falls to 5 feet and it takes a –2 penalty on attack rolls and to AC.

Lore: Galeb duhrs are enigmatic and taciturn rock creatures. A galeb duhr hammer is actually the nascent form of a galeb duhr, as yet unintelligent, gifted by the clan fathers to certain dwarves and other earth friends to serve as a living weapon against common enemies.
Someone who wields a galeb duhr hammer without the permission of the hammer’s creator faces the possibility of being hunted down and crushed (Knowledge [arcana] DC 15).

Prerequisites: Craft Magic Arms and Armor, stone shape.
Cost to Create: 2,500 gp (plus 312 gp for base item), 200 XP, 5 days.