Maiming is a +1 weapon ability. Maiming weapons may be identified by the "of Maiming" after the item type.
Maiming: This weapon has a twisted haft or grip and spikes along its blade, head, or point. Whenever you score a critical hit with this weapon it deals an amount of extra untyped damage depending on its critical multiplier: x2 - 1d6. x3 - 2d6. x4 - 3d6.