Golem, Seige (CR 12)

Gargantuan Construct
Alignment: Neutral
Initiative: +1(Dex); Senses: darkvision 60 ft., low-light vision, Listen +0, and Spot +0
Languages: Cannot speak

AC: 26 (-4 size, +1 Dex, +19 natural), touch 7, flat-footed 25
Hit Dice: 16d10+60 (148 hp); DR: 10/adamantine
Fort +5, Ref +6, Will +5
Speed: 30 ft.
Space: 20 ft./15 ft.
Base Attack +12; Grapple +34
Attack: 2 slams +18
Damage: Slams 4d8+10
Special Attacks/Actions: boulder 6d6+10, trample 4d8+15
Abilities: Str 30, Dex 12, Con -, Int -, Wis 11, Cha 1
Special Qualities: Construct traits, immunity to magic, Weaknesses: phase door, repel wood, warp wood, wood shape
Feats: -
Skills: Listen +0 and Spot +0
Advancement: -
Climate/Terrain: Any open, non-aquatic
Organization: None
Treasure/Possessions: None

Source: Cityscape

Boulder (Ex) A siege golem can launch a boulder from the catapult atop its back, dealing damage equal to 6d6 points + Str modifier (usually 10). This does not qualify as a standard ranged attack, but instead uses the rules for siege engines). The golem must succeed on a roll of ld20 + its base attack bonus (usually 12) against DC 15. The boulder has a range increment of 200 feet, and range penalties apply as normal.

If the roll succeeds, the boulder hits the targeted square, dealing damage to all creatures or objects in that square (Reflex DC 15 half). If the roll fails, determine the direction of the miss as described in Siege Engines.

It takes the golem two move actions to reload the catapult from a store of boulders it keeps slung to its underside, so it can fire every round if it does nothing else, or less frequently if it moves or takes other actions. The average siege golem carries 3d4 boulders.

Immunity to Magic (Ex): A siege golem is immune to any spell or spell-like ability that allows spell resistance. In addition, certain spells and effects function differently against the creature, as noted below.

A warp wood or wood shape spell slows the golem (as the slow spell) for 1d6 rounds. A repel wood spell drives the golem back 120 feet and deals 3d12 points of damage.

A phase door spell cast directly on a siege golem negates its damage reduction and immunity to magic for 1d3 rounds. The golem gets no saving throw against any of these effects.

Trample (Ex): Reflex DC 26 half. The save DC is Strength-based.