The Ghostwalk Campaign Option was released only a short time before the D&D v.3.5 rules were. This document provides all the changes that should be made to the book to update it for use with the new rules. A few clarifications are included here as well.
Page 166, Monstrous Vampire:
Creating a Monstrous Vampire: Change "Monstrous vampire is a template" to "Monstrous vampire is an acquired template."
Delete "beast" from list of monster types to which the template can be applied.
Before Sample Monstrous Vampire section, add "Size and Type: The creature's type changes to undead (augmented aberration, animal, dragon, fey, giant, humanoid, magical beast, monstrous humanoid, or vermin). Do not recalculate base attack bonus, saves, or skill points. Size is unchanged."
Hit Dice: Increase all current and future Hit Dice to d12s.
Page 166, Monstrous Vampire:
Replace sample monstrous vampire entry with the following.
Sample Monstrous Vampire Yuan-Ti Abomination
Large Undead (Augmented Monstrous Humanoid)
Hit Dice: 9d12 (58 hp)
Speed: 30 ft. (6 squares), climb 20 ft., swim 20 ft.
Armor Class: 32 (-1 size, +3 Dex, +16 natural, +2 masterwork heavy shield, +1 bracers of armor +1, +1 deflection [ring of protection +1]), touch 12, flat-footed 29
Base Attack/Grapple: +9/+20
Attack: Masterwork scimitar +16 melee (1d8+7/18-20) or masterwork composite longbow (+4 Str bonus) +12 ranged (2d6+4/[TS]3) or slam +15 melee (1d8+7 plus energy drain)
Full Attack: Masterwork scimitar +16/+11 melee (1d8+7/18-20) and bite +10 melee (2d6+3 plus poison) or masterwork scimitar +16/+11 melee (1d8+7/18-20) and slam +10 melee (1d8+3 plus energy drain) or masterwork composite longbow (+4 Str bonus) +12/+7 ranged (2d6+4/[TS]3)
Space/Reach: 10 ft./10 ft.
Special Attacks:Aversion, blood drain, children of the night, constrict 1d6+10, create spawn, energy drain, dominate, improved grab, poison, produce acid, spell-like abilities
Special Qualities:Alternate form (vampire and yuan-ti abilities), chameleon power, damage reduction 10/silver and magic, darkvision 60 ft., detect poison, fast healing 5, gaseous form, resistance to cold 10 and electricity 10, scent, spell resistance 18, spider climb, turn resistance +4, undead traits, vampire weaknesses
Saves: Fort +3, Ref +11, Will +12
Abilities: Str 25, Dex 17, Con -- , Int 22, Wis 22, Cha 22
Skills: Bluff +14, Climb +14, Concentration +18, Craft or Knowledge (any two) +18, Hide +18*, Listen +28, Move Silently +22, Search +14, Sense Motive +14, Spot +28, Swim +15
Feats: AlertnessB, Blind-FightB, Combat Expertise, Combat ReflexesB, Dodge, Improved Initiative, Lightning ReflexesB, Mobility
Environment: Warm forests
Organization: Solitary, pair, gang (3-4), troupe (2-13 purebloods, 2-5 halfbloods, and 2-4 abominations), or tribe (20-160 purebloods, 10-80 halfbloods, and 10-40 abominations)
Challenge Rating: 9
Treasure: Double standard
Alignment: Usually chaotic evil
Advancement: By character class
Level Adjustment: +15
This vampire's slam attack is treated as a magic weapon for the purpose of overcoming damage reduction. The DC is 20 for the Will save against this vampire's domination ability, and for the Fortitude save to remove a negative level caused by its energy drain.
Aversion (Sp): A yuan-ti abomination can psionically create a compulsion effect targeting one creature within 30 feet. The target must succeed on a DC 20 Will save or gain an aversion to snakes for 10 minutes. Affected creatures must stay at least 20 feet away from any snake or yuan-ti, alive or dead; if already within 20 feet, they move away. A subject unable to move away, or one attacked by snakes or yuan-ti, is overcome with revulsion. This revulsion reduces the creature's Dexterity score by 4 points until the effect wears off or the subject is no longer within 20 feet. This ability is otherwise similar to antipathy as the spell (caster level 16th). The save DC is Charisma-based.
Constrict (Ex): An abomination deals 1d6+10 points of damage with a successful grapple check.
Improved Grab (Ex): To use this ability, an abomination must hit a Large or smaller creature with its bite attack. It can then attempt to start a grapple as a free action without provoking an attack of opportunity. If it wins the grapple check, it establishes a hold and can constrict.
Poison (Ex): Injury, Fortitude DC 14, initial and secondary damage 1d6 Con. The save DC is Constitution-based.
Produce Acid (Sp): An abomination has the psionic ability to exude acid from its body, dealing 3d6 points of acid damage to the next creature it touches, including a creature hit by its bite attack. If the yuan-ti is grappling, constricting, or pinning a foe when it uses this power, its grasp deals 5d6 points of acid damage. The acid becomes inert when it leaves the yuan-ti's body, and the yuan-ti is immune to its effects.
Spell-Like Abilities: At will -- animal trance (DC 18), entangle (DC 17); 3/day -- deeper darkness, neutralize poison (DC 20), suggestion (DC 19); 1/day -- baleful polymorph (DC 21; into snake form only), fear (DC 20). Caster level 10th. The save DCs are Charisma-based.
Chameleon Power (Sp): A yuan-ti abomination can psionically change the coloration of itself and its equipment to match its surroundings, granting it a +10 circumstance bonus on Hide checks.
Skills: The abomination receives a +8 racial bonus on Climb checks and can always choose to take 10 on Climb checks, even if rushed or threatened. A yuan-ti abomination 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.
Vampire Weaknesses: Unlike landbound vampires, a vampire with a natural swim speed is not harmed by immersion in water and can cross running water without penalty.
*Yuan-ti abominations using chameleon power gain a +10 circumstance bonus on Hide checks.