Creature Types
Each creature has one type, which broadly defines its abilities. Some creatures also have one or more subtypes. A creature cannot violate the rules of its subtype without a special ability or quality to explain the difference—templates can often change a creature's type drastically.
Aberration
An aberration has bizarre anatomy, strange abilities, an alien mindset, or any combination of the three.
Animal
An animal is a living, nonhuman creature, usually a vertebrate with no magical abilities and no innate capacity for language or culture. Animals usually have additional information on how they can serve as companions. An animal has an Intelligence score of 1 or 2 (no creature with an Intelligence score of 3 or higher can be an animal).
Construct
A construct is an animated object or artificially created creature. A construct has the following traits.
• No Constitution score. Any DCs or other statistics that rely on a Constitution score treat a construct as having a score of 10 (no bonus or penalty).
• Immunity to all mind-affecting effects (charms, compulsions, morale effects, patterns, and phantasms).
• Immunity to bleed, disease, death effects, necromancy effects, paralysis, poison, sleep effects, and stunning.
• Cannot heal damage on its own, but often can be repaired via exposure to a certain kind of effect (see the creature's description for details) or through the use of the Craft Construct feat. Constructs can also be healed through spells such as make whole. A construct with the fast healing special quality still benefits from that quality.
• Not subject to ability damage, ability drain, energy drain, exhaustion, fatigue, or nonlethal damage.
• Immunity to any effect that requires a Fortitude save (unless the effect also works on objects, or is harmless).
• Not at risk of death from massive damage, but is immediately destroyed when reduced to 0 hit points or fewer.
• A construct cannot be raised or resurrected.
• A construct is hard to destroy, and gains bonus hit points based on its size (included in its stat block).
• Constructs do not breathe, eat, or sleep.
Dragon
A dragon is a reptile-like creature, usually winged, with magical or unusual abilities.
Fey
A fey is a creature with supernatural abilities and connections to nature or to some other force or place. Fey are usually human-shaped.
Humanoid
A humanoid usually has two arms, two legs, and one head, or a humanlike torso, arms, and a head. Humanoids have few or no supernatural or extraordinary abilities, but most can speak and they usually have well-developed societies. They are usually Small or Medium (with the exception of giants). Every humanoid creature also has a specific subtype to match its race, such as human, dark folk, or goblinoid.
Humanoids with 1 Hit Die exchange the features of their humanoid Hit Die for the class features of a PC or NPC class. Humanoids with more than 1 Hit Die (such as giants) are the only humanoids who make use of the features of the humanoid type.
Magical Beast
Magical beasts are similar to animals but can have Intelligence scores higher than 2 (in which case the creature knows at least one language, but can't necessarily speak). Magical beasts usually have supernatural or extraordinary abilities, but are sometimes merely bizarre in their appearance or habits.
Monstrous Humanoid
Monstrous humanoids are similar to humanoids, but with monstrous or animalistic features. They often have magical abilities as well.
Ooze
An ooze is an amorphous or mutable creature, usually mindless. An ooze has the following traits.
• Mindless: No Intelligence score, and immunity to all mind-affecting effects (charms, compulsions, phantasms, patterns, and morale effects). Mindless creatures have no skills or feats. An ooze with an Intelligence score loses this trait.
• Blind (but have the blindsight special quality), with immunity to gaze attacks, illusions, visual effects, and other attack forms that rely on sight.
• Immunity to paralysis, poison, polymorph, sleep effects, and stunning.
• Oozes eat and breathe, but do not sleep.
Outsider
An outsider is at least partially composed of the essence (but not necessarily the material) of some plane other than the Material Plane. An outsider has the following traits.
• Unlike most living creatures, an outsider does not have a dual nature—its soul and body form one unit. When an outsider is slain, no soul is set loose. Spells that restore souls to their bodies, such as raise dead, reincarnate, and resurrection, don't work on an outsider. A different magical effect, such as limited wish, wish, miracle, or true resurrection, is required to restore it to life. An outsider with the native subtype can be raised, reincarnated, or resurrected just as other living creatures can be.
• Outsiders breathe, but do not need to eat or sleep (although they can do so if they wish). Native outsiders breathe, eat, and sleep.
Plant
This type comprises vegetable creatures. Note that regular plants, such as one finds growing in gardens and fields, lack Intelligence, Wisdom, and Charisma scores; even though plants are alive, they are objects, not creatures. A plant creature has the following traits.
• Immunity to all mind-affecting effects (charms, compulsions, morale effects, patterns, and phantasms).
• Immunity to paralysis, poison, polymorph, sleep effects, and stunning.
• Plants breathe and eat, but do not sleep.
Undead
Undead are once-living creatures animated by spiritual or supernatural forces. An undead creature has the following traits.
• No Constitution score. Undead use their Charisma score in place of their Constitution score when calculating hit points, Fortitude saves, and any special ability that relies on Constitution (such as when calculating a breath weapon's DC).
• Immunity to all mind-affecting effects (charms, compulsions, morale effects, patterns, and phantasms).
• Immunity to bleed, death effects, disease, paralysis, poison, sleep effects, and stunning.
• Not subject to nonlethal damage, ability drain, or energy drain. Immunity to damage to its physical ability scores (Constitution, Dexterity, and Strength), as well as to exhaustion and fatigue effects.
• Cannot heal damage on its own if it has no Intelligence score, although it can be healed. Negative energy (such as an inflict spell) can heal undead creatures. The fast healing special quality works regardless of the creature's Intelligence score.
• Immunity to any effect that requires a Fortitude save (unless the effect also works on objects or is harmless).
• Not at risk of death from massive damage, but is immediately destroyed when reduced to 0 hit points.
• Not affected by raise dead and reincarnate spells or abilities. Resurrection and true resurrection can affect undead creatures. These spells turn undead creatures back into the living creatures they were before becoming undead.
• Undead do not breathe, eat, or sleep.
Vermin
This type includes insects, arachnids, other arthropods, worms, and similar invertebrates. Vermin have the following traits.
• Mindless: No Intelligence score, and immunity to all mind-affecting effects (charms, compulsions, morale effects, patterns, and phantasms). Mindless creatures have no feats or skills. A verminlike creature with an Intelligence score is usually either an animal or a magical beast, depending on its other abilities.
• Vermin breathe, eat, and sleep.
Creature SubTypes
Some creatures have one or more subtypes. Subtypes add additional abilities and qualities to a creature.
Adlet Subtype: This subtype is applied to the strange humanoid wolf creatures called adlets, and to creatures related to adlets.
Air Subtype: This subtype is usually used for outsiders with a connection to the Elemental Plane of Air. Air creatures always have fly speeds and usually have perfect maneuverability. Air creatures treat Fly as a class skill.
Aquatic Subtype: These creatures always have swim speeds and can move in water without making Swim checks. An aquatic creature can breathe water. It cannot breathe air unless it has the amphibious special quality. Aquatic creatures always treat Swim as a class skill.
Archon Subtype: Archons are a race of celestials, or good outsiders, native to lawful good-aligned Outer Planes. An archon possesses the following traits.
• Darkvision 60 feet and low-light vision.
• Aura of Menace (Su) A righteous aura surrounds archons that fight or get angry. Any hostile creature within a 20-foot radius of an archon must succeed at a Will save to resist its effects. The save DC varies with the type of archon, is Charisma-based, and includes a +2 racial bonus. Those who fail take a –2 penalty on attack rolls, on saves, and to AC for 24 hours or until they successfully hit the archon who generated the aura. A creature that has resisted or broken the effect cannot be affected again by the same archon's aura for 24 hours.
• Immunity to electricity and petrification.
• +4 racial bonus on saves against poison.
• Teleport (Sp) Archons can use greater teleport at will, as the spell (caster level 14th), except that the creature can transport only itself and up to 50 pounds of carried objects.
• Truespeech (Su) All archons can speak with any creature that has a language, as though using a tongues spell (caster level 14th). This ability is always active.
Augmented Subtype: A creature receives this subtype when something (usually a template) changes its original type. Some creatures (those with an inherited template) are born with this subtype; others acquire it when they take on an acquired template. The augmented subtype is always paired with the creature's original type.
Asura Subtype: An asura has the following traits, unless otherwise noted in the creature's entry.
• Immunity to curses, disease, and poison.
• Resistance to acid 10 and electricity 10.
• +2 racial bonus on saving throws against enchantment spells.
• Telepathy.
• Elusive Aura (Su) Asuras exist within reality but apart from it. All but the least of asuras exude an aura that affects all creatures within the area as if by a nondetection spell. The size of the aura is proportional to the asura's power. The caster level check to attempt divination on creatures within the aura is 15 + the spell-like ability caster level of the asura creating the aura.
• Regeneration (Ex) The divine spark at the core of their being allows asuras to regenerate at varying rates. Good weapons and spells can kill an asura.
• Spell Resistance (Ex) Most asuras are resistant to magic and have an SR equal to 11 + their CR. Only the weakest asuras lack this ability.
• Summon (Sp) Asuras share the ability to summon others of their kind, typically another of their type or a small number of weaker asuras.
• An asura's natural weapons, as well as any weapons it wields, are treated as lawful and evil for the purpose of overcoming damage reduction.
• +6 racial bonus on Escape Artist checks and a +4 racial bonus on Perception checks.
Behemoth Subtype: A behemoth is a neutral Colossal magical beast of great strength and power. Behemoths possess the following traits unless otherwise noted.
• Blindsense 60 feet.
• Immunity to ability damage, aging, bleed, disease, energy drain, fire, mind-affecting effects, negative levels, paralysis, permanent wounds, petrification, poison, and polymorph. Some behemoths possess additional immunities.
• Regeneration (Ex) No form of attack can suppress a behemoth's regeneration—it regenerates even if disintegrated or slain by a death effect. If a behemoth fails a save against an effect that would kill it instantly, it rises from death 3 rounds later with 1 hit point if no further damage is dealt to its remains. It can be banished or otherwise transported away as a means to save a region, but the only way to truly kill a behemoth is to use miracle or wish to negate its regeneration (see below).
• DR 15/epic.
• SR equal to 11 + the behemoth's CR.
• Behemoths understand Aklo, but cannot speak.
• Behemoths eat, but do not breathe or sleep.
• Ruinous (Su) A behemoth's natural attacks penetrate damage reduction as if they were epic and magic, and ignore up to 20 points of hardness on objects struck. As a swift action, whenever it strikes a creature or object with a spell effect in place, it can attempt to dispel one randomly determined spell effect on that creature as if with a greater dispel magic (CL 20th).
• Unstoppable (Ex) If a behemoth starts its turn suffering from any or all of the following conditions, it recovers from them at the end of its turn: blind, confused, dazed, deafened, dazzled, exhausted, fatigued, nauseated, sickened, slowed, staggered, and stunned.
• Vulnerable to Miracles and Wishes (Su) A spell effect created by a miracle or wish spell is particularly effective against a behemoth. A spellcaster gains a +6 bonus on its caster level check to penetrate a behemoth's SR with a miracle or wish spell, and the behemoth suffers a –6 penalty on saves against these spells. A miracle or a wish spell can negate a behemoth's regeneration, but only for 1d4 rounds per casting.
Catfolk Subtype: This subtype is applied to the humanoid felines called catfolk and creatures related to catfolk.
Chaotic Subtype: This subtype is usually applied to outsiders native to the chaotic-aligned Outer Planes. Most creatures that have this subtype also have chaotic alignments; however, if their alignments change, they still retain the subtype. Any effect that depends on alignment affects a creature with this subtype as if the creature had a chaotic alignment, no matter what its alignment actually is. The creature also suffers effects according to its actual alignment. A creature with the chaotic subtype overcomes damage reduction as if its natural weapons and any weapons it wields were chaotically aligned.
Clockwork Subtype: Clockworks are constructs created through a fusion of magic and technology. They have the following traits unless otherwise noted.
• Winding (Ex) Clockwork constructs must be wound with special keys in order to function. As a general rule, a fully wound clockwork can remain active for 1 day per Hit Die, but shorter or longer durations are possible.
• Vulnerable to Electricity: Clockwork constructs take 150% as much damage as normal from electricity attacks.
• Swift Reactions (Ex) Clockwork constructs generally react much more swiftly than other constructs.
They gain Improved Initiative and Lightning Reflexes as bonus feats, and gain a +2 dodge bonus to AC.
• Difficult to Create (Ex) The time and gp cost required to create a clockwork is 150% of normal. Construction requirements in individual clockwork monster entries are already increased.
Cold Subtype: A creature with the cold subtype has immunity to cold and vulnerability to fire.
Daemon Subtype: Daemons are neutral evil outsiders that eat souls and thrive on disaster and ruin. They have the following traits unless otherwise noted.
• Immunity to acid, death effects, disease, and poison.
• Resistance to cold 10, electricity 10, and fire 10.
• Summon (Sp) Daemons share the ability to summon others of their kind, typically another of their type or a small number of less powerful daemons.
• Telepathy.
• Except where otherwise noted, daemons speak Abyssal, Draconic, and Infernal.
Demodand Subtype: Demodands are chaotic evil outsiders who stalk the Abyss. Unless otherwise noted in a creature's entry, demodands possess the following traits.
• Immunity to acid and poison.
• Resistance to fire 10 and cold 10.
• Summon (Sp) Demodands share the ability to summon others of their kind, typically another of their type or a small number of less powerful demodands.
• Faith-Stealing Strike (Su) When a demodand's natural attack or melee weapon damages a creature capable of casting divine spells, that creature must make a Will saving throw or be unable to cast any divine spells for 1 round. Once a creature makes this save, it is immune to further faith-stealing strikes from that particular demodand for 24 hours. The save DC is Charisma-based.
• Heretical Soul (Ex) All demodands gain a +4 bonus on saving throws against divine spells. In addition, any attempts to scry on a demodand using divine magic automatically fail. The caster can see the scryed area normally, but the demodand simply does not appear.
• Except when otherwise noted, demodands speak Abyssal, Celestial, and Common.
• A demodand's natural weapons, as well as any weapons it wields, are treated as chaotic and evil for the purpose of resolving damage reduction.
Demon Subtype: Demons are chaotic evil outsiders from the Abyss. Demons have the following traits unless otherwise noted in a creature's entry.
• Immunity to electricity and poison.
• Resistance to acid 10, cold 10, and fire 10.
• Summon (Sp) Demons share the ability to summon others of their kind, typically another of their type or a small number of less powerful demons.
• Telepathy.
• Except where otherwise noted, demons speak Abyssal, Celestial, and Draconic.
Devil Subtype: Devils are lawful evil outsiders that hail from the plane of Hell. Devils possess the following traits unless otherwise noted in a creature's entry.
• Immunity to fire and poison.
• Resistance to acid 10 and cold 10.
• See in darkness.
• Summon (Sp) Devils can summon others of their kind, typically another of their type or a small number of less powerful devils.
• Telepathy.
• Except when otherwise noted, devils speak Celestial, Draconic, and Infernal.
Div Subtype: Divs are neutral evil outsiders that sow misfortune and ruin. They have the following traits unless otherwise noted.
• Immunity to fire and poison.
• Resistance to acid 10 and electricity 10.
• See in Darkness (Su) Some divs can see perfectly in darkness of any kind, even that created by a deeper darkness spell.
• Summon (Sp) Some divs share the ability to summon others of their kind. Each entry describes the success chance and type of divs summoned.
• Telepathy.
• Except where otherwise noted, divs speak Abyssal, Celestial, and Infernal.
Earth Subtype: This subtype is usually used for outsiders with a connection to the Elemental Plane of Earth. Earth creatures usually have burrow speeds, and most earth creatures can burrow through solid rock. Earth creatures with a burrow speed possess tremorsense.
Elemental Subtype: An elemental is a being composed entirely from one of the four classical elements: air, earth, fire, or water. An elemental has the following features.
• Immunity to bleed, paralysis, poison, sleep effects, and stunning.
• Not subject to critical hits or flanking. Does not take additional damage from precision-based attacks, such as sneak attack.
• Elementals do not breathe, eat, or sleep.
Evil Subtype: This subtype is usually applied to outsiders native to the evil-aligned Outer Planes. Evil outsiders are also called fiends. Most creatures that have this subtype also have evil alignments; however, if their alignments change, they still retain the subtype. Any effect that depends on alignment affects a creature with this subtype as if the creature had an evil alignment, no matter what its alignment actually is. The creature also suffers effects according to its actual alignment. A creature with the evil subtype overcomes damage reduction as if its natural weapons and any weapons it wields were evil-aligned.
Fire Subtype: A creature with the fire subtype has immunity to fire and vulnerability to cold.
Giant Subtype: A giant is a humanoid creature of great strength, usually of at least Large size. Giants have racial Hit Dice and never substitute such Hit Dice for class levels like some humanoids. Giants have low-light vision, and treat Intimidate and Perception as class skills.
Good Subtype: This subtype is usually applied to outsiders native to the good-aligned Outer Planes. Most creatures that have this subtype also have good alignments; however, if their alignments change, they still retain the subtype. Any effect that depends on alignment affects a creature with this subtype as if the creature had a good alignment, no matter what its alignment actually is. The creature also suffers effects according to its actual alignment. A creature with the good subtype overcomes damage reduction as if its natural weapons and any weapons it wields were good-aligned.
Human Subtype: This subtype is applied to humans and creatures that are related to humans.
Incorporeal Subtype: An incorporeal creature has no physical body. An incorporeal creature is immune to critical hits and precision-based damage (such as sneak attack damage) unless the attacks are made using a weapon with the ghost touch special ability. In addition, creatures with the incorporeal subtype gain the incorporeal defensive ability (see page 296).
Kami Subtype: Kami are a race of native outsiders who serve to protect what they refer to as “wards”—animals, plants, objects, and even locations—from being harmed or dishonored. All kami are outsiders with the native subtype. A kami possesses the following traits unless otherwise noted in a creature's entry.
• Immune to bleed, mind-affecting effects, petrification, and polymorph effects.
• Resist acid 10, electricity 10, fire 10
• Although they are native outsiders, kami do not eat, drink, or breathe.
• Telepathy.
• Fast Healing (Ex) As long as a kami is within 120 feet of its ward, it gains fast healing. The amount of fast healing it gains depends on the type of kami.
• Merge with Ward (Su) As a standard action, a kami can merge its body and mind with its ward. When merged, the kami can observe the surrounding region with its senses as if it were using its own body, as well as via any senses its ward might have. It has no control over its ward, nor can it communicate or otherwise take any action other than to emerge from its ward as a standard action. A kami must be adjacent to its ward to merge with or emerge from it. If its ward is a creature, plant, or object, the kami can emerge mounted on the creature provided the kami's body is at least one size category smaller than the creature. If its ward is a location, the kami may emerge at any point within that location.
• Ward (Su) A kami has a specific ward—a creature with a 2 or lower Intelligence (usually an animal or vermin), a plant (not a plant creature), an object, or a location. The type of ward is listed in parentheses in the kami's stat block. Several of a kami's abilities function only when it is either merged with its ward or within 120 feet of it. If a kami's ward is portable and travels with the kami to another plane, the kami does not gain the extraplanar subtype on that other plane as long as its ward remains within 120 feet. If a ward is destroyed while a kami is merged with it, the kami dies (no save). If a ward is destroyed while a kami is not merged with it, the kami loses its merge with ward ability and its fast healing, and becomes permanently sickened.
Kyton Subtype: Kytons are a race of lawful evil outsiders native to the Plane of Shadow who feed on fear and pain. Kytons possess the following traits (unless otherwise noted in a creature's entry).
• Darkvision 60 feet.
• Regeneration (Ex) The extent of a kyton's regeneration varies according to type, and can be neutralized by good weapons, good spells, and silver weapons.
• Immunity to cold.
• Unnerving Gaze (Su) All kytons have a gaze attack that manipulates the perceptions of those who look upon them. An unnerving gaze has a range of 30 feet, and can be negated by a Will save—the exact effects caused by a particular kyton's unnerving gaze depend on the type of kyton. All kytons are immune to the unnerving gazes of other kytons. Unnerving gaze is always a mind-affecting fear effect. The save DC is Charisma-based.
Lawful Subtype: This subtype is usually applied to outsiders native to the lawful-aligned Outer Planes. Most creatures that have this subtype also have lawful alignments; however, if their alignments change, they still retain the subtype. Any effect that depends on alignment affects a creature with this subtype as if the creature had a lawful alignment, no matter what its alignment actually is. The creature also suffers effects according to its actual alignment. A creature with the lawful subtype overcomes damage reduction as if its natural weapons and any weapons it wields were lawful-aligned.
Leshy Subtype: A leshy is a nature spirit that inhabits the body of a specially grown plant. Regardless of their kind, all leshys share the following traits in addition to those granted by the plant type (unless otherwise noted in a creature's entry).
• Darkvision 60 feet and low-light vision.
• Immunity to electricity and sonic.
• Spell-Like Abilities: All leshys have pass without trace as a constant spell-like ability (CL equal to twice the leshy's HD).
• Change Shape (Su) All leshys can transform into plants, with results similar to the tree shape spell. Unlike that spell, this ability only allows transformation into Small plants of the same type of growth the leshy is related to. In this form, the leshy appears as a particularly healthy specimen of that particular plant. A leshy can assume plant form or revert to its true form as a swift action.
• Plantspeech (Ex) All leshys can speak with plants as if subject to a continual speak with plants spell, but only with species they are related to.
• Verdant Burst (Su) When slain, a leshy explodes in a burst of fertile energies. All plant creatures within 30 feet of a slain leshy heal 1d8 points of damage plus 1 point per HD of the slain leshy, and plant life of the same type as the leshy itself quickly infests the area. If the terrain can support this type of plant, the undergrowth is dense enough to make the region into difficult terrain for 24 hours, after which the plant life diminishes to a normal level; otherwise, the plant life has no significant effect on movement and withers and dies within an hour.
• Except where otherwise noted, all leshys speak Druidic and Sylvan.
Native Subtype: This subtype is applied only to outsiders. These creatures have mortal ancestors or a strong connection to the Material Plane and can be raised, reincarnated, or resurrected just as other living creatures can be. Creatures with this subtype are native to the Material Plane. Unlike true outsiders, native outsiders need to eat and sleep.
Oni Subtype: An oni is an evil spirit who takes humanoid form to become a native outsider. All oni have the following traits, unless otherwise noted in a specific creature's entry.
• Darkvision 60 feet and low-light vision.
• Change Shape (Su) All oni are shapechangers with the shapechanger subtype, but an oni takes only other shapes similar to its normal humanoid form.
• Humanoid Shape: As evil spirits clad in humanoid flesh, all oni possess a humanoid subtype.
• Regeneration (Ex) The rate of regeneration and damage type that suspends it depends on the type of oni, but is typically acid or fire.
Rakshasa Subtype: A rakshasa is a lawful evil spirit born into the Material Plane. A shapechanger that can walk with ease among humanoids, a rakshasa's true form has animalistic features and strangely jointed limbs. All rakshasas are native to the Material Plane, and have the following traits unless otherwise noted in a creature's entry.
• Darkvision 60 feet.
• Change Shape (Su) All rakshasas have the ability to change shape into any humanoid, as if using alter self.
• Detect Thoughts (Su) A rakshasa can detect thoughts as per the spell of the same name. This effect functions at CL 18th. A rakshasa can suppress or resume this ability as a free action. When a rakshasa uses this ability, it always functions as if it had spent 3 rounds concentrating and thus gains the maximum amount of information possible. The Will save DC to resist this effect is equal to 10 + 1/2 the rakshasa's HD + the rakshasa's Charisma modifier.
• Enhanced Defenses (Ex) All rakshasas have DR that can be penetrated by good and piercing weapons only. The amount of damage reduction varies according to the specific rakshasa. In addition, rakshasas are exceptionally resistant to magic, and possess SR equal to their CR + 15.
• Master of Deception (Ex) All rakshasas gain a +4 racial bonus on Bluff checks and a +8 racial bonus on Disguise checks.
• Spellcasting: All but the least of rakshasas have some level
of spellcasting ability, and can cast spells as sorcerers. The rakshasa's effective caster level as a sorcerer depends on its type, but is generally equal to its CR – 3.
Ratfolk Subtype: This subtype is applied to the humanoid rodents called ratfolk and creatures related to ratfolk.
Reptilian Subtype: These creatures are scaly and usually cold-blooded. The reptilian subtype is only used to describe a set of humanoid races, not all animals and monsters that are true reptiles.
Sasquatch Subtype: This subtype is applied to the humanoid beings called sasquatches and creatures related to sasquatches.
Shapechanger Subtype: A shapechanger has the supernatural ability to assume one or more alternate forms. Many magical effects allow some kind of shapeshifting, and not every creature that can change its shape has the shapechanger subtype.
Swarm Subtype: A swarm is a collection of Fine, Diminutive, or Tiny creatures that acts as a single creature. A swarm has the characteristics of its type, except as noted here. A swarm has a single pool of Hit Dice and hit points, a single initiative modifier, a single speed, and a single Armor Class. A swarm makes saving throws as a single creature. A single swarm occupies a square (if it is made up of non-flying creatures) or a cube (if it is made up of flying creatures) 10 feet on a side, but its reach is 0 feet, like its component creatures. In order to attack, it moves into an opponent's space, which provokes an attack of opportunity. A swarm can occupy the same space as a creature of any size, since it crawls all over its prey. A swarm can move through squares occupied by enemies and vice versa without impediment, although the swarm provokes an attack of opportunity if it does so. A swarm can move through cracks or holes large enough for its component creatures.
A swarm of Tiny creatures consists of 300 non-flying creatures or 1,000 flying creatures. A swarm of Diminutive creatures consists of 1,500 non-flying creatures or 5,000 flying creatures. A swarm of Fine creatures consists of 10,000 creatures, whether they are flying or not. Swarms of non-flying creatures include many more creatures than could normally fit in a 10-foot square based on their normal space, because creatures in a swarm are packed tightly together and generally crawl over each other and their prey when moving or attacking. Larger swarms are represented by multiples of single swarms. The area occupied by a large swarm is completely shapeable, though the swarm usually remains in contiguous squares.
Swarm Traits: A swarm has no clear front or back and no discernible anatomy, so it is not subject to critical hits or flanking. A swarm made up of Tiny creatures takes half damage from slashing and piercing weapons. A swarm composed of Fine or Diminutive creatures is immune to all weapon damage. Reducing a swarm to 0 hit points or less causes it to break up, though damage taken until that point does not degrade its ability to attack or resist attack. Swarms are never staggered or reduced to a dying state by damage. Also, they cannot be tripped, grappled, or bull rushed, and they cannot grapple an opponent.
A swarm is immune to any spell or effect that targets a specific number of creatures (including single-target spells such as disintegrate), with the exception of mind-affecting effects (charms, compulsions, morale effects, patterns, and phantasms) if the swarm has an Intelligence score and a hive mind. A swarm takes half again as much damage (+50%) from spells or effects that affect an area, such as splash weapons and many evocation spells.
Swarms made up of Diminutive or Fine creatures are susceptible to high winds, such as those created by a gust of wind spell. For the purpose of determining the effects of wind on a swarm, treat the swarm as a creature of the same size as its constituent creatures. A swarm rendered unconscious by means of nonlethal damage becomes disorganized and dispersed, and does not reform until its hit points exceed its nonlethal damage.
Swarm Attacks: Creatures with the swarm subtype don't make standard melee attacks. Instead, they deal automatic damage to any creature whose space they occupy at the end of their move, with no attack roll needed. Swarm attacks are not subject to a miss chance for concealment or cover. A swarm's stat block has “swarm” in the Melee entries, with no attack bonus given.
A swarm's attacks are nonmagical, unless the swarm's description states otherwise. Damage reduction sufficient to reduce a swarm attack's damage to 0, being incorporeal, or other special abilities usually give a creature immunity (or at least resistance) to damage from a swarm. Some swarms also have acid, blood drain, poison, or other special attacks in addition to normal damage.
Swarms do not threaten creatures, and do not make attacks of opportunity with their swarm attacks. However, they distract foes whose squares they occupy, as described below.
Swarms possess the distraction universal monster rule. Spellcasting or concentrating on spells within the area of a swarm requires a caster level check (DC 20 + spell level). Using skills that involve patience and concentration requires a DC 20 Will save.
Vanara Subtype: This subtype is applied to vanaras and creatures related to vanaras.
Vishkanya Subtype: This subtype is applied to vishkanyas and creatures related to vishkanyas.
Water Subtype: This subtype is usually used for outsiders with a connection to the Elemental Plane of Water. Creatures with the water subtype always have swim speeds and can move in water without making Swim checks. A water creature can breathe underwater and can usually breathe air as well. Water creatures treat the Swim skill as a class skill.
Core Rulebook