Interestingly, the Fiend Folio, whose contents I generally don't find to my liking, included the caryatid column, a creation of Jean Wells and an opponent I've often used to good effect. What follows is the version of this magical construct that I use in my Dwimmermount campaign.
The material in the quote box below is hereby designated Open Game Content via the Open Game License.
Number Appearing: 1d12 (1d12)
% in Lair: Nil
Movement: 60' (20')
Armor Class: 5
Hit Dice: 5
Save: F5 (see below)
Hoard Class: None
The caryatid column is akin to the stone golem in that it is a magical construct created by a spellcaster. Caryatid columns are always created for a specific defensive function. The caryatid column stands 7 feet tall and weighs around 1,500 pounds. Its smooth chiseled body is shaped as a beautiful woman. The column always wields a weapon (usually a longsword) in one of its hands. The weapon itself is constructed of steel, but is melded with the column and made of stone until the column animates.
Caryatid columns are programmed as guardians and activate when certain conditions or stipulations are met or broken (such as a living creature entering a chamber guarded by a caryatid column). A caryatid column attacks its opponents with its longsword. It does not move more than 50 feet from an area it is guarding or protecting.
Any weapon that strikes a caryatid column has a 40% chance to shatter into pieces. Magic weapons have a 5% less chance to shatter for each point of its combat bonus. Thus, a +2 sword has only a 30% chance to shatter. Due to their sturdy construction and magical nature, caryatid columns gain a +4 bonus to all their saving throws.