The petrified arm of a massive beast, Grendel's Arm can be wielded as a two-handed weapon that does 1d10 damage. The arm still retains a measure of its inherent ferocity; after it has been wielded as a weapon by a character, it strikes out on its own against the same foe with an attack bonus of +6.
On an attack roll of one, the wielder of the Arm must make a Saving Throw vs. Magic Device. On a failed Save, Grendel's Mother becomes alerted to the location of the bearer of her son's arm.
