Steel Watcher
Steel Watchers are a non-playable Construct race in Baldur's Gate 3. Steel Watchers are characterized by their imposing size and ability to self-destruct. They almost exclusively appear in the city of Baldur's Gate. During the quest Disable the Steel Watch, several Hellfire Watchers and a special Steel Watcher Titan can be found in Steel Watch Foundry. Karlach's heart is a prototype engine for the Steel Watchers. Three types of Steel Watchers are represented in the game:
With the exception of Steel Watcher Titan, Steel Watchers will gain the condition 
when they are close to 0
hit points. This is caused by the passive feature Failsafe Protocol. The explosion will deal 4d12+26
Fire damage in an area around the Watcher. This attack ignores 
resistance and 
immunity to Fire damage. Target will still take half damage on a successful 
Dexterity saving throw.
Related Items
The Steel Watcher Titan wields 
Gontr Mael, can be looted after killing the creature.
Steelwatcher Helmet
Hellfire Engine Crossbow
Watcher Greatsword