Golem, Emerald (CR 12)

Large Construct
Alignment: Always neutral
Initiative: +1 (Dex); Senses: darkvision 60 ft. and Listen +23
Languages: Cannot speak

AC: 27 (-1 size, +1 Dex, +17 natural), touch 10, flat-footed 26
Hit Dice: 12d10+30 (96 hp); DR: 10/adamantine
Fort +4, Ref +5, Will +5
Speed: 30 ft. (cannot run)
Space: 10 ft./10 ft.
Base Attack +9; Grapple +21
Attack: 2 slams +16 melee
Full Attack: 2 slams +16 melee
Damage: Slam 2d6+8
Special Attacks/Actions:
Abilities: Str 26, Dex 12, Con -, Int 10, Wis 12, Cha 1
Special Qualities: Emerald gates, magic immunity, construct
Feats: Awesome Blow; Cleave; Improved Bull Rush; Improved Sunder; Power Attack
Skills: Climb +23 and Listen +23
Advancement: 13-24 HD (Large); 25-36 HD (huge)
Climate/Terrain: Any land and underground
Organization: Solitary, pair or troop (3-5)
Treasure/Possessions: None (except heart)

Source: Monster Compendium: Monsters of Faerûn

Emerald Gates (Sp): 1d2 times per day, as a spell-like ability requiring a standard action, an emerald golem can create an emerald circle upon the ground that functions like the teleportation circle spell. Unless it has orders not to, the emerald golem is likely to step through the gate to the other side. An emerald gate lasts for 1d6 rounds. If the die result is a 6, the gate lasts for 1d6 hours. The destinations of emerald gates are, as far as wizards can tell, random.

Unlike the teleportation circle spell, which requires the caster to have been at the target location, the golems' emerald gates appear capable of going anywhere that any other emerald golem has ever been. The gates tend not to land underwater, inside volcanoes, or 300 feet up in the air, though safe and hospitable destinations cannot be counted on.

Magic Immunity (Ex): Emerald golems are immune to all spells, spell-like abilities, and supernatural effects, except for the following: Bigby's forceful hand, Bigby's grasping hand, Bigby's clenched fist, and Bigby's crushing hand affect the emerald golem normally Furthermore, these spells treat the golem as if it weighed only 500 pounds. A shatter spell affects the emerald golem per the spell's standard effects. A mending spell heals all of the golem's damage.

Construct: Immune to mind-influencing effects, poison, disease, and similar effects. Not subject to critical hits, subdual damage, ability damage, energy drain, or death from massive damage.

Emerald golems fight with their powerful fists.