A 9-foot tall magical construct that protects its master through a linked amulet
Created by powerful spellcasters, a Shield Guardian is a construct that protect its masters from harm. Each one is magically linked to a particular magical amulet and will protect its bearer at any cost. A shield guardian will always follow the amulet; if for some reason it and its amulet are separated by more than 100 feet, the construct will enter a dormant state, standing still and waiting impassively for the return of the amulet.
A shield guardian is 9 feet tall and weighs at least 1,200 pounds. A shield guardian cannot speak, but will understand commands given by its master. This construct has Darkvision with a range of 60 feet.
Note the attack bonus given above; a shield guardian is not good for much beyond defense. It is slow and straightforward in battle, bashing alternately with its heavy stone fists.
Basic Fantasy Field Guide Omnibus