A type of humanoid
Construct.
Iron Golems
Iron Golems are slow and heavily resistant to physical damage (except against Adamantine weapons). They are immune to bleed, death effects, disease, doomed, drained, fatigued, fire, healing, mental, nonlethal attacks, paralyzed, poison, sickened, spirit, unconscious, vitality and void damage. Some are able to exhale clouds of poisonous gas.
Iron Golems (and perhaps Golems in general) tend to have a particular vulnerability which hurts them extra, and another which heals them, such as acid and fire.