Clockwork Horror, Electrum (CR 4)

Small Construct
Alignment: Always lawful evil
Initiative: +2 (Dex)
Languages: Cannot speak

AC: 19 (+1 size, +1 Dex, +7 natural), touch 12, flat-footed 18
Hit Dice: 4d10+10 (32 hp)
Fort +1, Ref +2, Will +3
Speed: 30 ft.
Space: 5 ft./5 ft.
Base Attack +3; Grapple +0
Attack: Razor saw +5 melee, or pressure dart +5 ranged
Full Attack: Razor saw +5 melee, or pressure dart +5 ranged
Damage: Razor saw 1d8+1, pressure dart 2d4+1
Special Attacks/Actions:
Abilities: Str 12, Dex 13, Con -, Int 5, Wis 14, Cha 5
Special Qualities: Construct traits, electricity immunity; linked mind, spell vulnerability; SR 17
Feats: Point Blank Shot; Precise Shot
Skills: Climb +8
Advancement: -
Climate/Terrain: Any land and underground
Organization: Pair or component (3-8)
Treasure/Possessions: 50% coins, 50% good (gems only)

Source: Monster Manual II

Construct Traits: A clockwork horror 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. A clockwork horror has darkvision (60-foot range).

Linked Mind (Ex): All clockwork horrors within 10 miles of a gold, platinum, or adamantine horror are in constant communication. If one is aware of a particular danger, they all are. If one in a particular group is not flat-footed none, of them are. No clockwork horror in such a group is considered flanked unless they all are.

Spell Vulnerability (Ex): A clockwork horror is susceptible to the shatter spell, which blinds it for 1d4+1 rounds.

Clockwork horrors attack their foes with calculated, merciless precision. Lesser horrors unswervingly follow the orders of their superiors, fighting to the death if so commanded. In battle, clockwork horrors swarm around foes and whittle away at them while calling for reinforcements. A clockwork horror's weaponry is a part of its being, so it cannot be disarmed. When it dies, the gem in its brow disintegrates, and its body fuses into a mass of melted metal.

Electrum horrors advance into combat in precise battle lines, with the individual horrors spaced about 10 feet apart. They open fire with volleys of pressure darts. Upon closing with the enemy, some continue firing darts at perceived spellcasters or opponents using ranged weapons, while others slice away at nearby foes with their razor-sharp saws. After a battle, additional electrum horrors scavenge the area, retrieving fallen companions and any abandoned weapons for smelting down and making new horrors.