Vault guardian

Vault guardians were a unique variety of construct that were created and sold by the wizards of the Zhentarim. They were extremely valuable entities, costing upwards of 70,000 gp in materials and selling for over thrice that value.

Description
Vault guardians took the form of a variety of different creatures, from humanoids to common animals such as dogs. Their stone and metal bodies were decorated with a pattern of inscriptions that formed patterns over their front limbs and foreheads.

Abilities
What set a vault guardian apart from other constructs, such as stone or sand golems was the myriad of magical abilities it possessed. At will, they could readily detect and magical effects or auras, catch sight of any invisible creatures or items, and see things as they truly were.

Combat
A vault guardian made for a fairly straightforward combatant. It went directly after any foes and assailed them with its fists or forepaws. They were capable of reaching to both the astral and ethereal planes, and could harm beings that were typically only vulnerable to iron, silver, or enchanted, weapons.

In addition to the various resistances and immunities they possessed as constructs, guardians were nearly entirely resistant to the elements. They were exceptionally vulnerable to earth magic spells.

Ecology
As they were constructs, vault guardians had no need to rest, sleep, or eat. They could most often be found among the lords of Zhentil Keep.

History
The first vault guardians were actually made by Sembian mages and used to guard their mercantile companies. After some time, the secret of their creation was learned by members of the Zhentarim.