Iron Cobra (CR 2)

Medium Construct
Alignment: Always neutral
Initiative: +3 (Dex)
Languages: Cannot speak

AC: 17 (+1 size, +3 Dex, +3 natural), touch 14, flat-footed 14
Hit Dice: 2d10+20 (31 hp); DR: 5/adamantine
Fort +0, Ref +3, Will +0
Speed: 30 ft.
Space: 5 ft./5 ft.
Base Attack +1; Grapple +2
Attack: Bite +2 melee
Full Attack: Bite +2 melee
Damage: Bite 1d6+1
Special Attacks/Actions: Poison
Abilities: Str 12, Dex 17, Con -, Int -, Wis 11, Cha 1
Special Qualities: Construct traits, stalk victim, stealth, SR 19
Feats: -
Skills: Hide +13 and Move Silently +13
Advancement: 2-3 HD (Medium-size)
Climate/Terrain: Any land
Organization: Solitary
Treasure/Possessions: -

Source: Fiend Folio

Poison (Ex): An iron cobra delivers its poison after a successful bite attack. An iron cobra's internal poison reservoir holds three doses of poison; refilling the reservoir takes 1 minute. The effect of the poison depends on what kind of poison the cobra's creator filled its poison reservoir with; usually an iron cobra contains Medium-size monstrous spider venom (Fort DC 14 negates, initial and secondary damage 1d4 Str), although any injury poison can be used.

Construct Traits: An iron cobra 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 iron cobra has darkvision (60-foot range).

Stalk Victim (Su): An iron cobra can be ordered by its creator to stalk down and attack any creature whose name is known to the creator. The iron cobra can detect this creature's location, as if by the locate creature spell at 12th caster level.

Stealth (Ex): An iron cobra gains a +10 enhancement bonus on Hide and Move Silently checks.

An iron cobra has no intelligence of its own, but it can be commanded to undertake any number of actions by its creator. If its creator is not present, the cobra can undertake simple commands such as "Guard this treasure" or "Seek out and attack the king"); it follows these commands to the letter. In combat, a cobra's tactics are straightforward - bite until its victim dies.