This is a Golem on a time limit. It has 4 "arms" that also function as legs. It fights upright like a man, but looks more like some sort of beetle. It has an hourglass in the middle of its body. When the hour is up or the hourglass breaks (Tough to do since it is thick and enchanted glass) the golem stops moving and waits patiently to be flipped over, or for more sand to be poured through it. For labor purposes the Golem can be outfitted with a large sand pack, when all the sand is on the ground the Golem will stop working for the day.
This Golem is made as a relatively safe way for young monks to train in combat. The Golem is not designed to be lethal, but can be equipped with blades if desired.
To make a Timed Golem one must first construct the body out of lightweight metals and certain woods. But the animation is done by the ritually-enchanted hourglass and magical sands from holy places. Only the highest order of Master Monks knows the mystic ritual involved in creating the hourglasses required to animate the constructs and are not pleased when they are broken.
These Golems are used only by top-notch monasteries and will only be found in such.
"Flipped" - While exploring an ancient monastery of, possibly after these Golems became a secret, the PCs accidentally flip one over and have to fight it. It will be tough and the PCs may all end up unconscious only to wake up an hour later to find the thing inert.
"Delay them!" - Maybe some villain has gotten his hands on some of these and uses them to delay the PCs without actually killing them. Maybe some sort of Robin Hood type fellow.