Since I'm riding a wave of interest in turning Sarvaelen into a S&W setting, here are stats for some of the unique monsters of the world of the Watchers of the Sullen Vigil...
Ghuls of Camrinal
Hit Dice: 3
Attacks: two claws (+3 to hit, 1D6 damage each) and bite (+3 to hit, 1D4 damage plus ghul fever)
Armor Class: 7 
Saving Throw: 15
Special: ghul fever, cannibals, half-dead, fear immunity, disease immunity, +2 turn resistance
Alignment: any, but inevitably gravitate toward chaos
No. Encountered: solitary or in small groups (2-12)
Ghul Fever: once bitten by a ghul, the target must make a saving throw vs. the poison of the bite or suffer from a debilitating fever. The principle effect is 1D6 minutes long and induces nausea and severe cramping, causing the target to suffer a -4 penalty to attacks, saves and any other physical prowess checks the GM deems appropriate.
Cannibals: Ghuls are known cannibals. The ghuls of Aelghast restrain themselves, and feed only on their own (so far as anyone knows) and the dead (suspected but not proven; they are very careful to avoid being caught). Any ghul that feeds off of living kindred flesh may immediately recover 1D6 hit points.
Half-Dead Immortals: Ghuls don’t age. They look like zombies, with rotting skin and bones visible, clearly not being quite “alive” yet not dead, either. However they do breathe and effects which affect the living usually also harm them (except for diseases). Ghuls are susceptible to turn undead effects, but with a +2 bonus to the saving roll. They “appear” as undead on spells that detect such conditions, but with an eerie aura of half-life suggesting something unusual about them.
Seen Too Much: Ghuls have already experienced some amazing horrors in their time. Ghuls are immune to fear effects.
Disease Immunity: Ghuls are immune to the effects of all disease.
The ghuls are a survivor race, mutated descendants of a handful of Camrinal citizens that survived the apocalypse and kept their wits about them. Even hideously changed into half-dead beings the ghuls prosper, though in time it seems the madness inevitably creeps over them.
The ancient empire of Camrinal was a vast, dominant power that subjugated the old kingdoms to its rule about two hundred years ago. Camrinal not only ruled by force of arms but by force of magic as well, for it indulged the aristocracy of its era with a culture of free experimentation and arcane dabbling that eventually led to a magiocracy in which only those who demonstrated sorcerous talent were allowed to hold the reigns of power, ownership of property or positions of strength in the Empire. Magic had, in this now lost era two centuries gone, become ubiquitous.
When the fires of destruction rained down upon Camrinal in the Final Conflict, the vast majority of the old empire was wiped out, but many of its lesser citizens and a few elites survived. Today these survivors are mostly found as changed beings among the population known as the ghuls, but in some odd corners of the world there still exist untainted purebloods, though they often do not realize their own lineage.
As ghuls age they gradually begin to lose their mental faculties, and slowly go insane. When this happens they become feral creatures, driven purely by a desire to devour flesh. When a ghul dies or is slain, it returns within 1D4 days as an actual undead ghoul.
Hit Dice: 6
Attacks: two, by weapon (+6 attack, 1D8 cleaver or pick plus special, below)
Armor Class: 3 (17)
Saving Throw: 11
Special: slayer of mirth (deals double damage to surprised target that was laughing/happy); silver or +1 or better weapons required to hit; magic
No. Encountered: usually solitary but 10% chance of 1D4 working in a group
Slayer of Mirth: the feyril despise the happy, friendly or optimistic. A strike against an unsuspecting target that is in such a state deals double damage due to the sheer venom of the feyril attack.
Skin of the Goddess: The rugged skin of the feyril can only be harmed by magical or silvered weapons.
Magic Skill: feyril are usually (60% chance) magic users of INT 13-15 on average. They typically know the following spells as a wizard of 6th level experience, but will choose any spells that help hunt prey:
Level 1 (4/day): sleep, charm person, read magic, magic missile
Level 2 (2/day): Invisibility, Strength
Level 3 (2/day): Hold Person Slow
Feyril are short, dwarf-like men who have developed a superstitious reputation thanks to the folklore which precedes them. The stories speak of how feyril are not really men at all, but a curious sort of creature born from the turbulent, bubbling dreams of the mad goddess Matrigias, said to have been the first of the Old Gods, and that she was accosted in terrible ways by the male gods who were unable to control themselves. From this horrific union she became pregnant, bloated from one horizon to the next with the spawn of the world, and when she at last broke water she was destined to give birth to all of the animals of the world. The stories say that Matrigias was driven mad by the endless spawn of animals which crawled from her womb to populate the world, and that she shed unbearable tears of blood and water at the endless pain. From these tears grew the feyril, squat and toad-like little men that were described by some as almost like infants in appearance, but horribly wise to the world due to the suffering of their mother. The feyril crawled forth, to extinguish any joy or revelry where they found it. Such was it that when mankind was at last born into the world he could know joy, for the feyril had stolen all of the pain and suffering of their mother by then. It was only later that humanity came to fear the feyril, for they found the joy and merriment of men to be offensive, and sought to extinguish it by means of murder and fright.
Naga (of Nagapuram)
Hit Dice: 6+4
Attacks: one weapon (+6 attack, polearm 1D8+1 damage) and bite (+6 attacl, 1D4 damage plus venom below); or one bite or weapon and constriction (+6 attack, 1D8+2 damage)
Armor Class: 3 (17) or by armor
Saving Throw: 11
Special: constriction, naga venom
Movement: 9 (land) or 15 (swimming)
No. Encountered: 1D4 or 2D12
Naga Venom: if bitten by a naga, the target makes a saving throw against poison at -2 due the potent nature of the venom. If failed the target is paralyzed for 1D6X10 minutes. Naga can only perform this bite once every 2D4 hours, as it requires time to regenerate.
Magical Talent: naga are naturally skilled mages and clerics. Any given naga has a 10% chance of being a magic user or a 14% chance of being a cleric of 1D6 levels of skill. In any community of naga there is a 50% chance of a magic-user or cleric of at least 6+1D6 levels of the give class.
Naga in Sarvaelen are an ancient race, cursed long ago with the serpentine traits that mark their lineage. Once, or so the story goes, the Naga were among the greatest of the old ones, the races that predate modern men long ago. A series of ancient tomes, most of which are now lost to history called the “Yavandreth Manuscripts” tell a bit of the ancient tale of the naga. A mostly complete set of the four surviving tomes can be found at the Library of the Sun in the port city of Aramen, Aeronost’s southern port and capital of the so-called Stormsinger Coast province. There the lone monk Procosius maintains these books and remains the land’s foremost authority on Naga lore.
As legend goes, naga were once men, albeit of a breed of old that was naturally inclined to sorcery and spoke directly to the Old Gods but were changed in some forgotten time to the half men, half serpents they now are. The naga ruled all of Sammar in the south and were allied with Camrinal, but were cast down during the Great War two centuries ago. Their ancient king was the sorcerer Kaliya, a powerful necromancer and priest of the old gods revered by his people. These four gods they worshipped were said to grant great strength to the naga.
According to the Yavandreth Manuscripts, Kaliya did something to anger his gods. There are conflicting tales. One says he was to sacrifice his eldest child in honor of the gods and as a payment for his great necromantic talent, but he refrained from doing so and brought down a great curse upon his people. Another tale suggests something similar, but that it was his wife, Padmavati, could not bear to lose her child and so spirited him away before Kaliya could sacrifice the infant. Yet another tale says nothing of this curse induced by loss of sacrifice and instead suggests that the naga were formed when they sought to make a dark pact with the elder god called Dev Yama’Dragoth. Yama’Dragoth granted the naga their wish, giving them supreme power and immortality as sorcerers, but in exchange he took their humanity, leaving only the twisted, serpentine forms naga are known for today.
Whatever their origin, naga appear to be half men and half serpent, often with strongly reptilian facial features and sometimes the wide, decorative “hoods” of a cobra enveloping their head and neck. Naga are fearsome to behold. Naga are known for their poisonous bite, also a shared feature with the cobra, and they are exceptional swimmers, albeit not aquatic, a common misconception among humans since the only known kingdom of the naga is to be found on the Isle of Stoneblight, where the naga city of Nagapuramcan be found.
Nagapuram is an impressive, ancient city located on an expansive island about two hundred miles off the Stormsinger Coast in the Pavain Sea. The naga call the island Manak’tagar, and defend it vigorously from outsiders; one must seek a benefactor to vouch for a foreigner who seeks to visit the island and its amazing city of ancient monuments. Stories of travelers, diplomats and merchants indicate that there are ten thousand naga within the city and probably three times as many slaves, usually of humans from the south eastern kingdom of Sammar, which does not normally disturb the citizens of Aeronost who have frequently had to deal with hostile pirates from that distant land.
The island itself is ruled by the so called Living Goddess who goes by the name of Padmavati, the mythical first queen of the naga. Whether she styles herself a descendent or a reincarnation of this first naga queen is unknown, but she does believe she is a demigoddess, imbued with the powers of the current naga patron deity, Manasa.
The naga are a potent force locally, and the diplomats of Aeronost have sought to keep them as allies rather than enemies. Still, the naga are so feared that the often do as they will, and treat much of the Stormsinger Coast as their own domain. This has often led to unfortunate bloody conflicts between the soldiers and naval forces charged with protecting the dominion of the Pavain Sea and the forces of Nagapuram.
In the region of Aelghast, there is a small community of about one hundred naga who have taken up residence in the subterranean caverns around a sacred hot spring that they call Uk’halat. The hot spring has been turned into a shrine dedicated to the seven-headed serpent god called Agharda, said to have devoured the original four naga gods of old and absorbed their essence. It is believed by this remote group of exiles that the seven heads of Agharda represent the seven kingdoms of the naga, spread throughout the world, and that worshipping this deity will reunite the naga into a powerful force that will resume the mantle of rule again.
This worship of the seven-headed god is regarded as heresy by the Living Goddess Padmavati, as it was only a century ago that the cult of Agharda was embraced by her people. This period led to a vicious war with the distant eastern empire of Kadatha, and nearly led to the destruction of the naga kingdom. As a result of this conflict Agharda’s worshippers were forced into exile lest they be hung for heresy. This branch near Aeronost follows the fanatical priest Yazzad Sydaris, and calls their unique sect the “Sons of Sydaris” or simply Sydarites. They believe that Sydaris has a unique ability to channel the thoughts and speech of Agharda.