Automaton, Hammerer (CR 4)

Medium Construct
Alignment: Always neutral
Initiative: +0
Languages: Cannot speak

AC: 21 (+11 natural), touch 10, flat-footed 21
Hit Dice: 3d10+20 (36 hp)
Fort +1, Ref +1, Will +0
Speed: 20 ft.
Space: 5 ft./5 ft.
Base Attack +2; Grapple +9
Attack: Slam +10 melee
Full Attack: Slam +10 melee
Damage: Slam 2d8+10
Special Attacks/Actions:
Abilities: Str 25, Dex 11, Con -, Int -, Wis 9, Cha 4
Special Qualities: Construct traits, unreliable
Feats: -
Skills: -
Advancement: 6-8 HD (Medium-size); 9-15 HD (Large)
Climate/Terrain: Any land and underground
Organization: Solitary, pair, or team (3-5)
Treasure/Possessions: None

Source: Monster Manual II

Construct Traits: An automaton is immune to mind-affecting effects, poison, sleep, paralysis, stunning, disease, death effects, necromantic effects, and any effect that requires a Fortitude save unless it also works on objects. The creature is not subject to critical hits, subdual damage, ability damage, ability drain, energy drain, or death from massive damage. It cannot heal itself but can be healed through repair. It cannot be raised or resurrected. An automaton has dark-vision (60-foot range).

Unreliable (Ex): The shadow consciousness of an automaton is only quasi-real, like the consciousness of a creation such as a simulacrum. The creature is thus sometimes slow to react to the changing environment around it. At the beginning of each round in which an automaton attempts to act, roll 1d20. On a result of 11 or better, it acts normally; otherwise, it takes no action.

Like golems, automatons are mindless but tenacious combatants. Since they are emotionless in combat, they are not easily provoked. Automatons don't use weapons, even if ordered to do so. Instead, they always strike with their limbs, which are formidable weapons in themselves.

An automaton follows the orders of its creator. The creature can be commanded directly by its creator if the latter is within 60 feet and both visible and audible to the automaton. If uncommanded, an automaton follows its last instruction to the best of its ability, though it returns any attacks directed at it. Typically, the creator gives an automaton a simple set of instructions (such as "Remain in this area and attack all creatures that enter," or "Attack all bipedal creatures you see," or "Ring a gong and attack," or the like) to govern its actions in his or her absence.

Hammerers are not built for fancy tactical maneuvers, but they are still fearsome opponents. On the battlefield, commanders simply point teams of these constructs at the enemy and let them go.

The powerful hammer-arm that gives the hammerer its name is a nasty piece of business - heavy, solid, and deadly. The pincer-arm is used mainly for lifting things. The construct can attack with only one arm at a time, and although it can slam with either arm, it favors the hammer-arm for all its attacks.