Monster Stat #8:  the adamantite golem
  (from Adventurers #85)

frequency             very, very rare
# appearing           1
climate/terrain       any
movement              6"
armor class           -10
HD                    32 (144 hp)
thac0                 -3 (that's 3 below 0...)
# of attacks          1
damage/attack         5-60
special attacks       breath
special defenses      see below
magic resistance      see below
intelligence          Non-
alignment             Neutral
size                  L (20')

  Among constructs - golems, if you will - the iron golem has
always been considered the top-of-the-line model, the toughest,
the strongest, the most powerful.  The Adventurers thought so,
too, until, deep within the Underdark, they encountered a long-
dormant remnant of times long past.  This adamantine golem was
one of the mightiest foes they had (and still have) ever faced.
Constructed of pure adamantite, the hardest metal known to man
or dwarf, the golem was virtually indestructible.  Fully twenty
feet in stature, it was armed with a short sword, permanently
welded to its metallic hand.  This weapon, backed by the golem's
prodigous strength (equal to that of a titan), was capable of
dealing out terrible damage.  Presumably, other such golems (if
indeed there are any) might have varying weapons, perhaps a mace
or axe.  In addition to its weapon attack, the thing can breathe
forth a gout of thick grey vapors, once every three rounds, in
a 10' radius cloud.  Anyone breathing this gas must make a save
vs. petrification at -3 or be turned to stone, permanently.
  Being adamantite, the golem is utterly immune to fire, acid,
poison, mind-affecting spells and illusions, magic missiles,
and other such trivial forms of harm.  Cold attacks of rather
significant force will slow it for one round, while lightning
heals it, 1 hp/die of potential electrical damage.  Only the
most powerful magical weapons (+5 or greater enchantment) can
even nick the golem's adamantite body.  As stated, the thing
is nearly impossible to defeat; in fact, the Adventurers had
to flee rather than continue the fight.
  If the adamantite golem has any weaknesses, they lie in the
fact that the construct is extremely slow and ponderous (it
weighs in at an even 10,000 lbs.)  Whatever methods are used
to create such a golem are long-lost to man and elf, and such
information would be prized indeed.