Necrophidius (CR 2)

Medium Construct
Alignment: Always neutral
Initiative: +3 (Dex)
Languages: Understands Common, cannot speak

AC: 18 (+3 Dex, +5 natural), touch 13, flat-footed 15
Hit Dice: 2d10+20 (30 hp)
Fort +0, Ref +3, Will +0
Speed: 30 ft., climb 10 ft.
Space: 5 ft./5 ft.
Base Attack +1; Grapple +2
Attack: Bite +2 melee
Full Attack: Bite +2 melee
Damage: Bite 1d6+1 plus paralysis
Special Attacks/Actions: Dance of death, paralysis, sneak attack
Abilities: Str 13, Dex 16, Con -, Int -, Wis 11, Cha 12
Special Qualities: Construct traits
Feats: -
Skills: Climb +9, Hide +11, and Move Silently +11
Advancement: 3-5 HD (Medium-size); 6 HD (large)
Climate/Terrain: Any land and underground
Organization: Solitary or gang (2-5)
Treasure/Possessions: -

Source: Fiend Folio

Dance of Death (Su): A necrophidius can sway in a hypnotic manner, riveting the attention of any creature within 30 feet that can see it. Creatures that fail a Will saving throw (DC 12) are dazed (can take no actions but can defend themselves) for as long as the necrophidius continues its dance. Creatures that make their saving throws can avert their eyes from the necrophidius as if they were avoiding a gaze attack (50% chance per round of not having to make a saving throw, 20% miss chance on attacks against the necrophidius). A necrophidius can move up to its normal speed as a move action even if performing its dance of death. This is a mind-affecting effect.

Paralysis (Su): A creature bitten by a necrophidius must succeed on a Will saving throw (DC 12) or be paralyzed and unconscious for 10 minutes.

Sneak Attack (Ex): Anytime a necrophidius's target is denied a Dexterity bonus, or when a target is flanked by a necrophidius, the necrophidius deals an additional 2d6 points of damage on a successful melee attack.

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

Skills: A necrophidius has a +8 racial bonus on Hide and Move Silently checks. It also has a +8 racial bonus on Climb checks and can always choose take 10 on Climb checks, even if rushed or threatened.

The creature's normal method of attack is to hide, and then stealthily approach and sneak attack an unwary target. If confronted by multiple foes or by a creature aware of its presence, it uses its dance of death ability to allow it so approach its enemies and bite.