Well,
I consider the golem to be done as it is in my previous post

, but if you want me to integrate BOZ's suggestions...
Siren, Ravenloft
Medium Undead
Hit Dice: 4d12 (26 hp)
Initiative: +2
Speed: 20 ft. (4 squares), swim 50 ft.
Armor Class: 14 (+2 Dex, +2 natural), touch 12, flat-footed 12
Base Attack/Grapple: +2/+4
Attack: Claw +4 melee (2d4+2/19-20/x2)
Full Attack: 2 claws +4 melee (2d4+2/19-20/x2)
Space/Reach: 5 ft./5 ft.
Special Attacks: Augmented critical, captivating song, cursed wound, illusory appearance
Special Qualities: Darkvision 60 ft., spell resistance 14, undead traits
Saves: Fort +1, Ref +3, Will +4
Abilities: Str 15, Dex 14, Con -, Int 13, Wis 12, Cha 14
Skills: Bluff +9, Disguise +2*, Intimidate +9, Listen +6, Perform (Song) +7, Spot +6, Swim +10
Feats: Ability Focus (Captivating Song), Persuasive
Environment: Any aquatic
Organization: Solitary or school (2-8)
Challenge Rating: 4(?)
Treasure: Standard
Alignment: Always evil (usually neutral)
Advancement: (by character class? 5 - 12 HD (Medium)?)
Level Adjustment: - (+3?)
Ravenloft sirens speak Common and Aquan.
Augmented Critical (Ex): A Ravenloft siren continually sharpens its claws on the rocks on which it lives, making them deadly weapons. The siren’s claws threaten a critical hit on a natural attack roll of 19–20.
Captivating Song (Su): When a siren sings, all creatures within a 6000(?)-foot spread must succeed on a DC 16 Will save or become captivated. This is a sonic mind-affecting charm effect. A creature that successfully saves cannot be affected again by the same siren’s song for 24 hours. The save DC is Charisma-based and includes the siren's Ability Focus feat.
A captivated victim travels toward the siren, taking the most direct route available. If the path leads into a dangerous area (through flame, off a cliff, or the like), that creature gets a second saving throw. Captivated creatures can take no actions other than to defend themselves. (Thus, a fighter cannot run away or attack but takes no defensive penalties.) A victim within 5 feet of the siren sits there and offers no resistance to the monster’s attacks. However, any attack by the siren allows the victim to attempt a new Will save against the song. The effect continues for as long as the siren sings and for 1 round thereafter. A bard’s countersong ability allows the captivated creature to attempt a new Will save.
Cursed Wound (Su): The damage a Ravenloft siren deals doesn’t heal naturally and resists healing spells. A character attempting to cast a conjuration (healing) spell on a creature damaged by a Ravenloft siren must succeed on a DC 18 caster level check, or the spell has no effect on the injured character.
Illusory Appearance (Su): The Ravenloft siren's true from is shrouded by a illusion that shows her as a voluptous mermaid, as though with a disguise self spell. Anyone seeing the siren may attempt a Will save (DC 18) to disbelieve the illusion. Captivated victims suffer a -8 penalty to that save. Any attack by the siren allows the victim to attempt a new Will save to disbelieve the illusion. The Save DC is Charisma-based, and includes a +4 racial bonus.
Skills: A Ravenloft siren has a +8 racial bonus on any Swim check to perform some special action or avoid a hazard. It can always choose to take 10 on a Swim check, even if distracted or endangered. It can use the run action while swimming, provided it swims in a straight line. *When using its illusory appearance ability, a Ravenloft siren gets an additional +10 circumstance bonus on Disguise checks.