Herein you will find monsters mostly converted from the D20 SRD but also some original and lovecraft-inspired beasts, all suiting a Sword & Sorcery milieu. All are for the ACKS ruleset. See attachments for ACKS stat-tables.

The Aboleths are old, unfathomable creatures, the product of aeons past. They were old when the Serpentmen were young; they might have been old even when this world has formed from a stellar nebula. Where they came from remains a mystery, as the Aboleths themselves are tight-lipped about their ultimate origin. But as each of them is old, their knowledge is enormous. They spend ages in their underwater lairs, brooding, plotting... With endless patience. A single Aboleth, intelligent beyond the Human ability to understand, may be the centrepiece of a massive conspiracy, spun across the centuries towards an end known only to that alien mastermind.

The Aboleth itself is a revolting, green but pink-bellied, fishlike amphibian found primarily in subterranean lakes and rivers, or deep beneath the oceans. Four pulsating blue-black orifices line the bottom of its body and secrete gray slime smelling like rancid grease; it has four long tentacles used for grabbing, whipping and manipulating objects. It uses its tail for propulsion in the water and drags itself along with its tentacles on land. An Aboleth weighs about 6,500 pounds.

An Aboleth in combat utilizes its mind, as well as its watery lair, to its advantage. First, three times a day, it may Enslave a sentient creature; the victim must save vs. Spells, or become the Aboleth's mental thrall, fully under the creature's command, as per the Enslave spell. An Enslaved creature obeys the Aboleth's telepathic commands until freed by Remove Curse, and can attempt a new save vs. spells every 24 hours to break free. The control is also broken if the Aboleth dies or travels more than 1 mile from its slave. An Aboleth also possesses the following mental powers for use at will, as per the spells of these names: ESP, Hypnotic Pattern, Phantasmal Force, Hallucinatory Terrain.

A blow from an Aboleth's tentacle might cause a terrible affliction. A creature hit by such a tentacle must save vs. Polymorph or begin to transform over the next 1d4+1 minutes, the skin gradually becoming a clear, slimy membrane. An afflicted creature must remain moistened with cool, fresh water or take 1d12 points of damage every 10 minutes. The slime reduces the creature's armour class by 1 (but never to less than 0). A Cure Disease spell cast before the transformation is complete will restore an afflicted creature to normal. Afterward, however, only Restore Life and Limb may cure the affliction.

An Aboleth underwater surrounds itself with a viscous cloud of mucus, roughly 1 foot thick. Any creature coming into contact with and inhaling this substance must save vs. Polymorph or lose the ability to breathe air for the next 3 hours. An affected creature suffocates in 2d6 minutes if removed from the water. Renewed contact with the mucus cloud and failing another Fortitude save continues the effect for another 3 hours. This effect may be removed by Cure Disease.

Most Aboleths breed (from captured slaves), Skum - revolting fish-amphibian-men, to serve as their hand, ears and eyes outside their watery lair. These creatures possess a slimy skin, and may breath indefinitely both under and outside of water. While rarely armed with weapons, they possess a powerful bite, as well as sharp claws. Skum lack much organization  or willpower of their own, and care little for treasures. Their presence usually signifies the existence of an Aboleth lair in the vicinity.

Sometimes, when a mortal, out of immense desperation and utter madness, commits suicide, his spirit lingers where he died, forever babbling in utmost insanity. An Allip is such a tormented spirit; it craves only revenge and unrelentingly pursues those who tormented it in life and pushed it over the brink. Alternatively, it haunts the place of its horrible death, a bane upon the living. This undead being appears as a distorted variant of its mortal form, swirling like mist in the air. Its touch is the touch of madness - when an Allip successfully hits an opponent, the victim suffers 1d4 points of damage, and 1 point of WIS is drained for 8 turns. Should a being be drained to WIS 2, it lapses into absolute madness, screaming and flailing at unseen visages. At 0, it permanently transforms into an Allip.

The creature also constantly mutters and whines to itself, creating a hypnotic effect. All sane creatures within 60 feet of the Allip must save vs. Spells or be affected as though by a Hypnotic Pattern spell for 2d4 rounds. Creatures that successfully save cannot be affected by the same Allip's babble for 24 hours. Also, Anyone targeting an Allip with an ESP, mind control, or other telepathic ability or spell makes direct contact with its tortured mind and loses 1d4 points of WIS until the next sunrise.

Like other undead, Allips are immune to the effects of sleep, charm, and hold spells. Allips are turned as Mummies.

An Aranea is an intelligent, shapechanging spider with sorcerous power. It is not necessarily an evil creature, though its spidery nature, combined with the creature's longevity, yields itself to plotting. In its natural form, an Aranea resembles a giant spider, with a humpbacked body a little bigger than a human torso. It has fanged mandibles like a normal spider. Two small arms, each about 2 feet long, lie below the mandibles. Each arm has a hand with four many-jointed fingers and a double-jointed thumb. An Aranea weighs about 150 pounds. The hump on its back houses its well-developed brain.

An Aranea's natural form is that of a monstrous spider. It may assume two other forms. The first is a unique human-sized humanoid; an Aranea in its humanoid form always assumes the same appearance and traits. In humanoid form, an Aranea cannot use its bite attack, webs, or poison, but may cast spells, wear armour and use any weapon useable by a human being. The second form is a man-sized spider-humanoid hybrid. In hybrid form, an Aranea looks like a humanoid at first glance, but a successful roll of 16+ reveals the creature's fangs and spinnerets. The Aranea, in this form, retains its bite attack, webs, and, but may also wield weapons and wear armour. When in hybrid form, an Aranea's speed is 90' (30').  An Aranea remains in one form until it chooses to assume a new one. A change in form cannot be dispelled, nor does an Aranea revert to its natural form when killed.

An Aranea avoids physical combat and uses its webs and spells when it can. In a battle, it tries to immobilize or distract the most aggressive opponents first. Araneas often subdue opponents and hold them for ransom rather than poisoning or killing them; alternatively, the creature may offer its captured victim "an offer it cannot refuse". Any opponent bitten by the Aranea, however, widow must make a saving throw versus Poison; failure indicates death after 1 turn. Aranea may cast Arcane spells as a level 3 Mage; they prefer illusions and enchantments and avoids direct damage spells. In spider or hybrid form, an Aranea may also throw a web up to six times per day, as in the Web spell.

The Giant Cockroach is a giant - and particularly disgusting - version of the common cockroach, reaching up to 2 feet in length not including antennae (which add another foot!) and weighting about 40 pounds. While giant cockroaches feed on trash and other smelly substances found in sewers and not on flesh, and are cowardly insects to boot, they will fight to defend their nests and territories, and may stage an opportunistic attack on weak adventurers. Note that while a giant cockroach saves as a level 1 Fighter against most attacks, it saves as a level 10 Fighter vs. poison and is immune to most disease-based attacks. The Geckomen of Queddar consider these insects to be a delicacy and raise herds of them in fenced-off cave warrens, fattening them on refuse to be roasted over the campfire.

The Dreaded Balroach, on the other hand, is a horribly nauseating cockroach larger than a horse. While it is an omnivore and scavenger rather than a predator, it will fiercely defend its lair and may see weak adventurers as food. Its horrid appearance and unsightly behaviour make it a menace whenever it emerges from its sewerly warrens to scavenge in the dwellings of men! The Balroach is immune to poisons and diseases. Besides its powerful mandibulae, its disgusting appearance and horrible smell offer it protection; any adventurer who comes within sight of a Balroach must save vs. Poison or suffer from a severe nausea, causing a -4 penalty to all attack rolls, saving throws and proficiency checks.

These vicious, tentacle-handed, predators lurk underground, grabbing whatever prey happens by to feast upon its flesh and bones. Its hands and feet have spiny pads that help the choker grip almost any surface. The creature weighs about 35 pounds. A choker likes to perch near the ceiling, often at intersections, archways, wells, or staircases, and reach down to attack its prey. A choker attacks creatures of almost any size, but prefers lone prey of its size or larger. If one is very hungry, it may attack a group, but it waits to grab the last creature in line. Once a victim has been grabbed by the Choker, the creature chokes him, dealing an automatic 1d3+3 damage to the victim each round until the victim either escapes (requiring a proficiency throw of 18+; for each point of Strength adjustment, modify the result of the die roll by +/- 4; characters with the Contortionism proficiency gain an additional +4 to this throw), dies, or the Choker dies. Although not particularly dexterous, a choker is supernaturally quick. It can take an extra action (such as an attack) or move during its turn each round.

Concocted in some eldritch laboratory of the ancient Serpentmen as a living engine of war, the Chuul is a horrible mix of crustacean, insect, and serpent. This abomination lurks submerged or partially submerged in murky water, awaiting intelligent prey to devour. Although amphibious, Chuuls are not good swimmers and actually prefer to be on land or in very shallow water when they attack. A Chuul is about 8 feet long and weighs 650 pounds. A Chuul prefers to wait by the shore, submerged in murky water, until it hears nearby prey (in or out of the water) that it can attack with surprise.

The Chuul grabs with its claws and constricts its foe, then passes the opponent to its paralytic tentacles. It tries to always have one claw free, so if it faces a large number of opponents, it drops a paralyzed or dead victim and continues attempting to grab, constrict, and paralyze the rest. On a successful hit by a Chuul's claw, it is also able to constrict a victim for an additional 3d6+5 points of damage. The constriction continues on subsequent rounds. The hold may be broken on a roll of 1 on 1d6 (add the victim's Strength bonus to the range, so a Strength of 16 would result in a range of 1-3 on 1d6); breaking the hold takes a full round.

A victim grabbed by the Chuul's claw are also grasped by its tentacles, which exude a paralytic secretion. Anyone held in the tentacles must make each round a save vs. paralysis on the Chuul's turn or be paralyzed for 6 rounds. While held in the tentacles, paralyzed or not, a victim automatically takes 1d8+2 points of additional damage each round from the creature's mandibles. Chuuls may live indefinitely on land and under water and are immune to poison and disease.

The mighty Coatl is a servant and emissary of Ixchala, the Lawful goddess of Lizardmen. This feathered serpent – actually, a feathered and winged cross between a serpent and a monitor lizard – is 12 feet long, with a wing-span of 15 feet. It vibrates in a rainbow of brilliant colours as it flies through the clouds. For Lawful Lizardmen, this is a harbinger of good luck and hope. For the Serpentmen of old, however, this was the harbinger of their destruction by Ixchala's righteous wrath. Highly intelligent and imbued by virtue, the Coatl seeks to protect the innocents and the cause of Law – of Lizardman civilization – and to punish the followers of Chaos.

A Couatl uses its ESP ability on any creature that arouses its suspicions. Since it is highly intelligent, a Couatl usually casts spells from a distance before closing. If more than one Couatl is involved, they discuss their strategy before a battle. Coatls may constrict their foes with their long, serpentine body - on a successful hit on an enemy, the Coatl constricts its victim for an additional 2d8+6 points of damage. The constriction continues on subsequent rounds. The hold may be broken on a roll of 1 on 1d6 (add the victim's Strength bonus to the range, so a Strength of 16 would result in a range of 1-3 on 1d6); breaking the hold takes a full round. Furthermore, any creature bitten by a Coatl must save vs. Poison or die in 1d6 rounds from its potent venom.

Coatls are imbued by Ixchala with potent mental and magical powers. At will, a Coatl may use Detect Evil, Detect Good, ESP, Invisibility and Dimension Door, and may communicate with any sentient creature telepathically regardless of language barriers. It may also casts spells as a level 9 Cleric. Finally, a Coatl may polymorph at will to the shape of any Lizardman-sized humanoid.

Craymen are hideous humanoid crayfish, standing 5'6'' upright and sporting sharp pincers instead of hands. They have a yellowish-brown chitin exoskeleton, and two red eyes on top of long eyestalks emanating from their hammer-shaped heads. Completely amphibious, a Crayman may live indefinitely on land or underwater. Craymen have a rudimentary intelligence and a primitive social structure, and communicate with each other using a series of inhuman clicks. They have the equivalent of Infravision, which works underwater as well. Craymen eat all kinds of watery life such as crabs, fish, crayfish and squid, as well as algae, but crave the taste of landlubber flesh, and, in addition, sacrifice any captives to their dread lord, K'tulu.

The many-tentacled octopoid Darkmantle hangs from a ceiling by a muscular "foot" at the top of its body. It can look like a stalactite, by holding its tentacles stiffly under itself, or like a lump of rock, spreading its tentacles so the membrane between them covers its body. Its shell and skin usually resemble limestone, but a darkmantle can change its color to match almost any type of stony background, and thus may surprise opponents on a roll of 4- (rather than 2-) on 1d6.  A Darkmantle is about 4 feet long from the tips of its tentacles to the top of its head. It weighs about 30 pounds.

In addition to its camouflage and surprise abilities, the Darkmantle has several unique abilities, making it an effective ambush predator in a subterranean environment. First, once a day, it may cast Darkness, as per the spell, as if cast by a level 5 Mage. Also, on a successful hit on an enemy with its slam attack, the Darkmantle constricts its victim for an additional 1d4+1 points of damage. The constriction continues on subsequent rounds. The hold may be broken on a roll of 1 on 1d6 (add the victim's Strength bonus to the range, so a Strength of 16 would result in a range of 1-3 on 1d6); breaking the hold takes a full round. Finally, the Darkmantle may "see" in pitch darkness using echolocation, up to 90'; however, as it uses high-frequency sounds to locate its prey, a Silence spell effectively blinds the creature.

"I think their predominant colour was a greyish-green, though they had white bellies. They were mostly shiny and slippery, but the ridges of their backs were scaly. Their forms vaguely suggested the anthropoid, while their heads were the heads of fish, with prodigious bulging eyes that never closed. At the sides of their necks were palpitating gills, and their long paws were webbed. They hopped irregularly, sometimes on two legs and sometimes on four. I was somehow glad that they had no more than four limbs. Their croaking, baying voices, clearly used for articulate speech, held all the dark shades of expression which their staring faces lacked ... They were the blasphemous fish-frogs of the nameless design - living and horrible."
- H.P. Lovecraft, "The Shadow Over Insmouth"

The Deep Ones are a race of aquatic monstrosities, part fish, part frog and part man, who have inhabited the oceans around Kanahu for aeons. They battled the Serpentmen for dominance; vied for control with the mysterious Visitors; and were the targets of numerous holy wars by the Lizardmen followers of Lawful Ixchala. And yet, they remain; dwelling under the waves in their magnificent, if terrible, reef cities, where they pay tribute to their father-god, Dagon, as well as to their over-god, K'tulu.

The Deep Ones are not content with living underwater, however. In service of their Chaotic masters, they seek to infiltrate coastal communities, intermixing with the local Human population, and tainting the blood of Men with their terrible curse. Indeed, the old, deposed nobility of Harat, mostly chased from their mansions and seaside castles by Hardun's Army of the Free, were, and still are, hybrids of Men and Deep Ones. This racial template represents these hybrids, who continually devolve from humanity to aquatic monstrosities.

A Hybrid is a 0 level Human tainted with Deep One blood; in addition to its abilities noted above, he may hold his breath for up to 1 turn (10 minutes), and sometimes uses this ability to ambush unsuspecting prey who wander near murky water. Without close inspection, however, Hybrids may pass for normal, if ugly, Humans, and they may use this fact to lure unsuspecting victims to their seaside villages, and even to stay at their inns, and then capture them and sacrifice them to their dread god K'tulu. They usually wear unkempt leather armour and fight using spears, tridents, hand axes and daggers. Each Hybrid gang is led by a ringleader with AC4, 1HD and 1d4+4 hit points. Each Warband is led by a war-chief with AC5, 1+1 HD, 1d4+5 hit points and +1 to damage and to hit due to greater strength. A Deep One Hybrid village will be led by a headman with AC 6, 3 HD and +2 to damage to to-hit from Strength; as long as he is alive, his cohorts will gain a +2 bonus to Morale; in addition, there will be a minor Priest of Dagon in each village, with AC 5, 3 HD, and spellcasting as a level 3 Cleric.

A full Deep One is a monstrosity combining the features of a man, a frog and a fish. It may breath freely both under and above water, has Infravision and is immune to disease and ageing. Deep Ones have thick scales protecting their bodies and attack with their claws and teeth. Each Deep One gang is led by a champion with AC 8, 4HD and +1 bonus to both attacks and damage from Strength. Each Warband is led by a war-chief with AC 8, 6 HD and +2 to to-hit and damage rolls due to his massive strength. A Deep One village is led by a prince with AC9, 8 HD, and +2 to damage to to-hit from Strength; as long as he is alive, his cohorts will gain a +1 bonus to Morale; in addition, there will be a Priest of Dagon in each Deep One village, with AC 8, 7 HD, and spellcasting as a level 7 Cleric.

The dungeon-dwelling Destrachan looks like some bizarre, nonintelligent dinosauroid, but it's an incredibly crafty sadist with a sharp, malign intellect. A Destrachan has a pair of complex, three-part ears that it can adjust to be more or less sensitive to various sounds. It is blind, yet hunts with a sense of hearing more precise than most creatures' sight. From its tubular mouth, a Destrachan emits carefully focused harmonics, producing sonic energy so powerful it can shatter a stone wall. So skilled is a Destrachan at controlling the sounds it emits that it can choose what type of material to affect with its attack.  A Destrachan is about 10 feet long from its mouth to the tip of the tail and weighs about 4,000 pounds. It uses echolocation to find its way unerringly in the dark, as if it possessed perfect eyesight. Lacking real eyes, however, this monster is immune from gaze attacks or any other effects based on eyesight, and, furthermore, saves against sonic or other auditory attacks as a level 12 Fighter. The Destrachan uses its claws only as a last resort or to finish off foes weakened by its sonic attacks. It often enters battle with surprise if possible. It first focuses on destroying metal armour and weapons and then changes to harmonics that disrupt flesh.

The Destrachan's main offensive power is its Destructive Harmonics – a powerful sonic attack. The creature may blast sonic energy in a cone up to 80 feet long, or, alternatively, it may also use this attack to affect any creatures or objects within a 30-foot radius. It can tune the harmonics of this destructive power to affect different types of targets. First, it may disrupt soft tissue and rend bone, dealing 4d6 points of damage to all living beings within the affected area (a save vs. Paralysis is allowed for half damage). Alternatively, it may focus its harmonics on knocking out foes rather than slaying them; this attack deals 6d6 points of nonlethal damage to all within the area (a save vs. Paralysis is allowed for half damage). Finally, when using a third form of harmonics, a Destrachan may choose between wood, stone, metal, or glass. All objects made of the chosen material within the area of affect are shattered on a roll of 15+ (if carried by a character or creature, the carrier may save vs. Paralysis instead in order to avoid losing the object. Magical or advanced technological objects are immune from this attack.

The Digester, created from dinosaur stock by foul magicks, is a hunting and eating machine equipped with a powerful acid-spraying natural weapon where its head should have been. It stands about 5 feet tall and is 7 feet long from snout to tail and weighs about 350 pounds. When it is not hungry (which is rarely), it lies low and avoids most other creatures. When hunting, it looks about for a likely target, then charges forth and delivers a gout of acid. If the initial attack is insufficient to kill the prey, the digester attacks with its hind feet until it can spray acid again. As an ambush predator, the Digester has +2 to all surprise rolls.

A Digester may spray acid in a 20-foot cone, dealing 4d8 points of damage to everything in the area. Once a digester uses this ability, it may not use it again for 1d4 rounds. The creature may also produce a concentrated stream of acid that deals 8d8 points of damage to a single target within 5 feet. In either case, a save vs. Breath Weapons halves the damage.

The Alamosaurus is an enormous sauropod herbivore, ranging up to 80' in length, with a shoulder height of 20' and a weight of approximately 30 tons. At this size, even Tyrannosauruses will hesitate to attack, unless the Alamosaurus is weak, or a youngster separated from its herd; when in a herd, virtually no predator will dare hunt this giant creature. An Alamosaurus, therefore, has little to fear from predators, and is rarely aggressive unless cornered, or unless defending its young. When it does attack, however, it uses its sheer weight to trample any smaller aggressor; against Human-sized or smaller creatures, it gains +4 to-hit to such an attack. While some tribes and city-states tame Alamosauruses to serve as giant beasts of burden, their slow pace and non-aggressive nature make them ill-suited to use as war-beasts.

Armoured to the hilt with bony plates and armed with a massive club of a tail capable of crushing most predators, the Ankylosaurus has the abilities, as well as the necessary temper, to defend itself from any perceived threat. This herbivorous dinosaur is quick to anger, and views most other creatures of Man-size or larger as potential predators, hence to be minced with its crushing tail. At the length of 30' and with a weight of 6 tons, this is a difficult, but rewarding, challenge for hunters, and its meat may feed an entire tribe of barbarians for a few days.