His chamber is characterized by two iron maidens and a bloody chest (glows like a Resplendent Chest and has similar quality of loot) in front of a furnace. Touching the chest will cause Garrach to yell "You think to take my treasure? You shall not leave this room!" (to which the character will respond). Garrach then gets of of his iron maiden to attack the intruders.
In combat, he is slower than other zombies, but has Plagued and Poison Enchanted affixes. In earlier versions of the game, being hit by either of these would also halve the player's armor.