For convenience, I've combined all the monsters that previously appeared on the website into one post.

Charred Horror
Huge Undead
Hit Dice: 12d12 (78 hp)
Initiative: -1
Speed: 30 ft. (6 squares)
Armor Class: 24 (-2 size, -1 Dex , +17 natural), touch 7, flat-footed 24
Base Attack/Grapple: +6/+24
Attack: Slam +14 melee (2d6+10 plus 1d6 fire)
Full Attack: 2 slams +14 melee (2d6+10 plus 2d6 fire)
Space/Reach: 15 ft./15 ft.
Special Attacks: Double damage against object, heat, trample (2d6+15 plus 2d6 fire)
Special Qualities: Cinder cloud, damage reduction 10/magic and slashing, darkvision 60 ft., dispel animation, immunity to fire, low-light vision, plant traits, undead traits
Saves: Fort +4, Ref +5, Will +9
Abilities: Str 30, Dex 8, Con -, Int 6, Wis 12, Cha 16
Skills: Hide +1*, Listen +11, Move Silently +4, Spot +11
Feats: Awesome Blow, Improved Bull Rush, Improved Sunder, Lightning Reflexes, Power Attack
Environment: Temperate forests
Organization: Solitary
Challenge Rating: 9
Treasure: None
Alignment: Always neutral evil
Advancement: 8-16 HD (Huge), 17-21 HD (Gargantuan)

This dead burned-out tree is nothing but black and grey charcoals, still warm with lingering flame. But some mockery of life animates it into a fiery engine of destruction that shuffles and creaks through the woods.

----Not all undead were once creatures of flesh and blood. The detestable charred horrors are the twisted corpses of once-noble treants who died by the flame. Risen from the dead as still-burning undead, they seek to spread the pain of their fiery demise to other trees.
----While retaining only a fraction of the intelligence they displayed in life, many charred horrors still have enough awareness to cast blame for their deaths. These horrors lay such blame squarely at the feet of the so-called defenders of the forest: druids, rangers, and possibly good forest creatures like dryads and unicorns. The undead creatures take great pleasure in destroying any glens still guarded by them, showing them the depth of their failure to protect the trees.
----No one knows for certain why some treants rise as charred horrors and others, even others who die by fire, do not. One druidic scholar has posited that charred horrors were treants who, in the last moment of their life as they burn, comes to actually find pleasure in their own fiery demise. Such an unnatural enjoyment of their own destruction catches the attention of whatever dark gods revel in such things, and they grant the plant creatures an unholy second chance.
----Charred horrors are as tall as living treants, but their bodies have been hollowed by fire, making them weigh only half as much. They still remember the languages they spoke in life: Common and Sylvan.

----Charred horrors are savage in combat, striving to destroy all opponents and burn down as many trees as they can. They take cruel delight in needless destruction, setting forests, buildings, and anything else in its path aflame.
----Heat (Ex):A charred horror is still aflame with fire deep within its trunk and limbs. Its slam attack deals additional fire damage, and any successful unarmed attack against it (including natural weapon attacks) inflicts 2d6 points of fire damage against the attacker. The charred horror can also set very flammable objects on fire by touching them.
----Cinder Cloud (Ex): The burning wood that forms the body of the horror is filled with hot cinders. These are released in a choking cloud whenever a physical attack successfully inflicts damage against it (by either overcoming or bypassing its damage reduction). The cinder cloud forces any creatures within a 10-foot radius to make a DC 19 Fortitude save or be sickened for 1d6 rounds. Creatures that do not need to breathe are immune to this effect. The save is Charisma-based (as the charred horror has no Constitution score).
----Dispel Animation (Su): The undead power of the charred horror can disrupt the animate trees ability of a living treant. If a charred horror moves within 100 feet of a tree animated by liveoak (whether cast by a treant or a druid), the effect is automatically dispelled.
----Double Damage against Objects (Ex): A charred horror that makes a full attack against an inanimate object or structure deals double regular slam damage as well as double fire damage.
----Plant Traits: A charred horror also retains the immunities granted by its former life as a plant. They are thus immune to polymorph and have low-light vision, in addition to all normal undead traits.
----Trample (Ex): Reflex save DC 26 half. The save DC is Strength-based.
----Skills: A charred horror has a +15 racial bonus on Hide checks made within a burned forest (including one still on fire). While this may seem like an esoteric skill bonus, keep in mind that a charred horror tends to create burned out forests wherever it goes.


Medium Outsider (Good, Native)
Hit Dice: 11d8+44 (93 hp)
Initiative: +7
Speed: 30 ft. (6 squares) (mithril shirt); base 30 ft., Fly 90 ft. (Good)
Armor Class: 22 (+1 Dex , +4 mithril shirt, +7 natural), touch 11, flat-footed 21
Base Attack/Grapple: +11/+14
Attack: silvered morningstar[/I] +16 melee (1d8+2 plus 1d6 fire) OR composite longbow (Mighty +3) +14 ranged (1d8+3) OR scorching ray +14 ranged touch (4d6 fire)
Full Attack: silvered morningstar +14/+14/+9/+9/+4 melee (1d8+2 plus 1d6 fire) OR composite longbow (Mighty +3) +14/+9/+4 ranged (1d8+3) OR scorching ray +14 ranged touch (4d6 fire)
Space/Reach: 5 ft./5 ft.
Special Attacks: Burning hands, scorching ray, spell-like abilities
Special Qualities: Damage reduction 10/cold iron, darkvision 60 ft., immune to fire, outsider traits, resistance to cold 10 and sonic 10, spell resistance 19
Saves: Fort +11, Ref +10, Will +6
Abilities: Str 16, Dex 16, Con 18, Int 10, Wis 8, Cha 16
Skills: Balance +5, Bluff +13, Diplomacy +9, Hide +13, Intimidate +18, Knowledge (the planes) +5, Jump +5, Listen +20, Move Silently +13, Search +21, Sense Motive +12, Spot +20, Tumble +10
Feats: Endurance (B), Fly-by Attack, Improved Initiative (B), Improved Two-Weapon Fighting, Two-Weapon Fighting, Weapon Focus (morningstar)
Environment: Any Upper Plane
Organization: Solitary or warband (2-5)
Challenge Rating: 8
Treasure: Standard plus two silvered morningstars and mithril shirt.[/I]
Alignment: Often neutral good
Advancement: By character class
Level Adjustment: +4

A powerfully-muscled humanoid with magnificent red and orange feathered wings, this creature's gaze is strong and piercing. It wears sparkling golden chainmail and carries a longbow and a pair of silvered morningstars.

----The fenixborn are a race of celestials with the blood of the mysterious Phoenix in their veins. Their heritage is clear from their red wings and natural fire magic, as well as their inherent desire to battle evil. Fenixborn often appear in groups of other celestials, such as guardinals and archons, because they have no cities on the Upper Planes to call their own. They often travel the planes on a never-ending personal crusade for evil-and a place to call their own.
----Fenixborn are always consumed with a passion to do good. They often make poor choices in the pursuit of their cause, leading wiser celestials to look down on them with a mixture of pity and bemusement. If the fenixborn notice the snide comments, they make no mention of it. Or perhaps their yearning to fit in with the likes of the angels and archons causes them to suffer through it in silence.
----Fenixborn stand between 6 and 7 feet in height with about a 12 foot wingspan, and weigh 200 to 300 lbs. They speak their Celestial, Common, and Ignan.

----Fenixborn love to attack quickly and with savage ferocity, bashing an opponent with twin flaming morningstars. Against tough opponents, though, they will instead use their great speed to strafe the enemy with arrows or scorching rays. They greatly rely on their ability to shrug off most weapons, often attacking without waiting to see whether their opponents are capable of harming them or not.
----Burning Hands (Su): All melee attacks made by the fenixborn inflict an additional 1d6 points of fire damage.
----Spell-like Abilities (Sp): At will: flame arrows, see invisibility, light. 3/day: cure serious wounds, haste (self only), protection from evil. Caster level 6th.
----Scorching Ray (Su): A fenixborn can start a blazing fire with a single glance. They may blast foes with a scorching ray from their eyes at will. Caster level 6th.
----Skills: A fenixborn gains a +8 racial bonus to Listen, Search, and Spot skill checks.


Gingerbread Golem
Diminutive Construct
Hit Dice: 2d10 (11 hp)
Initiative: +6
Speed: 50 ft. (10 squares)
Armor Class: 22 (+4 size, +6 Dex , +2 natural), touch 18, flat-footed 20
Base Attack/Grapple: +1/–14
Attack: Slam +2 melee (1d2–3)
Full Attack: Slam +2 melee (1d2–3)
Space/Reach: 0 ft./0 ft.
Special Attacks: None
Special Qualities: Construct traits, darkvision 60 ft., direction sense, low-light vision, magic immunity, staleness, uncanny dodge
Saves: Fort +0, Ref +7, Will +1
Abilities: Str 4, Dex 23, Con –, Int 8, Wis 12, Cha 10
Skills: Escape Artist +11, Hide +18, Jump +5, Knowledge (geography) +0, Move Silently +8, Tumble +14
Feats: Run
Environment: Any
Organization: Solitary
Challenge Rating: 2
Treasure: None
Alignment: Always neutral
Advancement: 3–4 HD (Diminutive), 5–6 HD (Tiny)

----This 8-inch long cookie is crudely shaped in the form of a humanoid and given eyes and mouth with delicious-looking white frosting.

----Gingerbread golems are tasty man-shaped cookies transformed into construct messengers, designed for delivering complex communications over long distances. They are temporary creations, eventually going stale after a few weeks, but exist long enough to fulfill their duties.
----Unlike most golems, gingerbread golems are somewhat intelligent and can remember and repeat anything told to them. This makes them a superior form of message carrier than, say, a pigeon, because they can actually answer questions posed by the recipient regarding the message, such as, “How long ago were you sent?” or “Were you seen by anyone on your way here?” Because they have short “life” spans, they are generally created for a specific message, and are often abandoned after that, left to dry up in an odd corner of the kitchen.
----Gingerbread golems can be directly commanded by their creator if he or she is within 60 feet, but as they are useless in battle that is rarely the case. Instead, the creator usually gives them complex instructions to deliver their messages, such as, “Bring this message to the Earl of Hogton, who lives in Hogton Castle.” The golem’s natural direction sense will lead him to the castle automatically. The creator might also instruct him to proceed at top speed, or to ensure that no one sees or captures him, or any other qualifier the golem is capable of understanding.
----Gingerbread golems speak any languages known by their creators.

----Gingerbread golems do not fight—they flee, and very effectively. Most combats involving a gingerbread golem are situations where someone is attempting to intercept the message the golem carries, either by destroying it or (tougher still) capturing it. Their intelligence makes them quite good at evading foes, allowing them to run or hide as necessary to continue their journey.
----Very rarely, an evil bard might craft evil gingerbread cookies as secret assassins. In this case, he or she would replace their Run feat with the Weapon Finesse feat and arm them with a little poisoned dagger (giving them an attack line of “Diminutive dagger +11 melee (1 plus poison)”.)
----Direction Sense (Su): A gingerbread golem always knows how to get to any destination with which its creator is familiar. Its knowledge is only as good as that of its crafter, though; if the creator is misinformed, then so is the golem. The gingerbread golem is also treated as being under the effects of the know direction spell at all times.
----Magic Immunity (Ex): A gingerbread golem is immune to any spell or spell-like ability that allows spell resistance. In addition, certain spells and effects function differently against the creature, as listed below:
  • A purify food and drink spell can stave off staleness for a single day. Do not count the day the spell is cast towards determining the onset of staleness; if already going stale, the spell also restores 2 lost Dexterity points (but does otherwise not reverse the process).
  • Any fire effect burns the soft cookie body of the the gingerbread golems, reducing its speed by 5 feet, but grants it damage reduction 1/— and increases its natural armor bonus to +3. This effect can only be achieved once, and it is reversed if the golem is returned to freshness by purify food and drink. (Some creators deliberately burn their golems to make them tougher.)

----Uncanny Dodge (Ex):A gingerbread golem retains its Dexterity bonus to AC even if it is caught flat-footed or struck by an invisible attacker. However, it still loses its Dexterity bonus to AC if immobilized.
----Staleness (Ex): A gingerbread golem stays fresh for two weeks after its creation. Every day thereafter, the golem must make a Fortitude save (DC 10) or start to go stale. Once staleness begins, the golem loses 2 points of Dexterity each day. When its Dexterity equals 0, the golem has gone completely stale; it is destroyed at that time.
----Construct Traits: Gingerbread golems are immune to all mind-affecting effects, poison, sleep effects, paralysis, stunning, disease, death effects, and necromancy effects. They cannot be healed damage on their own, though they can be repaired. They are not subject to critical hits, nonlethal damage, ability damage, ability drain, fatigue, exhaustion, and energy drain.
----Skills: Gingerbread golems have a +4 racial bonus to Escape Artist and Tumble skill checks.

----Ginger is a rare spice in most medieval societies, with a single ounce costing about 10 gp. Cooking up a gingerbread golem requires additional arcane ingredients as well, and the body costs 30 gp total. Baking the body requires a Profession (baker) skill check (DC 15) and takes 1 day.
----CL 5th, Craft Construct, animal messenger, expeditious retreat, know direction. Price 200 gp. Cost to Create: 130 gp + 8 XP.


Piranha Swarm
Tiny Animal (Aquatic, Swarm)
Hit Dice: 5d8+8 (30 hp)
Initiative: +2
Speed: Swim 40 ft. (8 squares)
Armor Class: 15 (+2 Dex , +3 natural), touch 12, flat-footed 13
Base Attack/Grapple: +3/-
Attack: Swarm (2d6)
Full Attack: Swarm (2d6)
Space/Reach: 10 ft./0 ft.
Special Attacks: Distraction, superior swarm
Special Qualities: Feeding frenzy, swarm traits, tremorsense
Saves: Fort +5, Ref +6, Will +0
Abilities: Str 2, Dex 14, Con 12, Int 2, Wis 8, Cha 2
Skills: Hide +4, Jump +4, Move Silently +4, Swim +4
Feats: Improved Initiative, Toughness
Environment: Warm aquatic
Organization: Solitary or school (2-8)
Challenge Rating: 3
Treasure: None
Alignment: Always neutral
Advancement: -

A school of silver fish, each with a wide mouth filled with sharp teeth.

----Piranha are a razor-toothed carnivorous fish that are fierce enough individually. When they gather in large groups, however, they can devour an adventurer in seconds. The fish are a common danger in tropical rivers, where schools feed on other fish or land animals that fall into the water, but adventurers more commonly encounter them as part of a death trap of some sort. They are often added to moats, pit traps, or underground rivers as a cheap and deadly method of keeping out unwanted intruders.
----An individual piranha is no more than two feet long at the most, but swarms can cover a much larger area.

----Piranha will attack living creatures that they encounter, but will become particularly aggressive if they smell the blood of an injured creature. They have been known to even leap out of the water to attack a creature standing to near the surface of a river.
----Feeding Frenzy (Ex):Whenever a living creature is injured within the tremorsense range of a piranha swarm (including a creature injured by the swarm itself), the swarm automatically enters a feeding frenzy on its next turn as a free action. A swarm in a feeding frenzy inflicts 1d6 additional damage with its swarm attacks and is immune to mind-affecting spells and effects. The frenzy continues as long as the swarm can sense any other living creature within their tremorsense range, and for an additional 2d4 rounds afterwards. If a creature enters their tremorsense range before the frenzy expires, it continues as if uninterrupted.
----When in a feeding frenzy, piranha might even attack other fish within the same swarm! Whenever a piranha swarm in a feeding frenzy takes damage from a slashing or piercing source (other than its itself), the swarm must make a Will saving throw (DC 10) at the start of its next turn. If it fails, the swarm suffers 1d6 points of additional damage as the fish devour one or more of their own.
----Distraction (Ex): Any living creature that begins its turn with a piranha swarm in its space must succeed on a DC 13 Fortitude save or be nauseated for 1 round. The save DC is Constitution-based. Even with a successful save, spellcasting or concentrating on spells within the area of the swarm requires a Concentration check (DC 20 + the spell level).
----Superior Swarm (Ex): With their hundreds of needle-like teeth, a swarm of piranha is exceptionally deadly and deals more swarm damage than their Hit Dice would otherwise indicate.
----Swarm Traits: A swarm has no clear front or back and no discernable anatomy, so it is not subject to critical hits or flanking. As a swarm made up of Tiny creatures, a piranha swarm takes half damage from slashing and piercing weapons.
----Reducing a swarm to 0 hit points or fewer causes the swarm 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 another.
----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 if the swarm has an intelligence score and a hive mind. A swarm takes a -10 penalty on saving throws against spells or effects that affect an area, such as many evocation spells or grenadelike weapons. If the area effect attack does not allow a saving throw, the swarm takes double damage instead.
----A swarm rendered unconscious by means of subdual damage becomes disorganized and dispersed, and does not re-form until its hit points exceed its subdual damage.
----Tremorsense (Ex): Piranha have such an acute sense of smell within the water that they can notice creatures that move through the water. Piranha swarms can locate creatures within 60 feet using tremorsense. Opponents still have total concealment against the piranha swarm (though swarm attacks ignore concealment).
----Skills: The piranha swarm gains 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.


Temple Gargoyle
Small Construct
Hit Dice: 6d10+10 (43 hp)
Initiative: +3
Speed: 30 ft. (6 squares), fly 40 ft. (good)
Armor Class: 19 (+3 Dex , +6 natural), touch 13, flat-footed 16
Base Attack/Grapple: +4/+1
Attack: Claw +8 melee (1d4+2)
Full Attack: 2 claws +8 melee (1d4+2)
Space/Reach: 5 ft./5 ft.
Special Attacks: Smite evil, water spout
Special Qualities: Construct traits, damage reduction 5/magic, darkvision 60 ft., magic circle against evil.
Saves: Fort +2, Ref +5, Will +2
Abilities: Str 14, Dex 17, Con -, Int 13, Wis 16, Cha 10
Skills: 27 Hide +15*, Listen +12, Move Silently +10, Spot +12
Feats: Combat Expertise, Flyby Attack (B), Improved Disarm, Weapon Finesse
Environment: Any
Organization: Solitary or wing (2-12)
Challenge Rating: 4
Treasure: None
Alignment: Always good (any)
Advancement: -

This creature looks like a small statue of a winged beast of some kind-except, of course, that it is moving.

----A temple gargoyle is a small stone figure animated with a willing spirit from the Upper Planes. Unlike most constructs, the gargoyle is quite intelligent, capable of defending its church without explicit instructions. Clerics often craft temple gargoyles as permanent defenders of a specific temple, designing the gargoyle's shape to fit into a specific niche in the building's façade.
----Temple guardians stand no more than 3 feet tall but weigh over 80 lbs. They speak Celestial and Common.

----Temple gargoyles fight to defend their home from evil influences, though they are occasionally employed to simply protect a sensitive area of the temple from nosy parishioners.
----Magic Circle Against Evil (Su):A temple gargoyle is always under the effect of a magic circle against evil. This effect can be dispelled (as if cast by a 11th level caster), but the temple gargoyle can reactivate it as a free action on its turn.
----Smite Evil (Su): Once per day, a temple gargoyle may make a normal melee attack to deal extra damage equal to its Hit Dice (in this case, +6) against an evil foe.
----Water Spout (Su): The temple gargoyle can let loose a blast of water from its mouth as a standard action. The water splashes all creatures within a 30-foot line, inflicting 3d6 points of nonlethal damage (Reflex half DC 13). The temple gargoyle can spout water at will.
----Three times per day, the temple gargoyle may instead spout holy water. The spray has the same effect except against undead or evil outsiders; they instead suffer 6d6 points of normal damage (Reflex half DC 16). The holy property of the water dissipates immediately after the spray.
----Skills: Temple gargoyles have a +2 racial bonus to Hide, Listen, and Spot. The Hide bonus increases by +10 when concealed against worked stone in a setting where statuary is evident.

----A temple gargoyle's body must be crafted from a block of stone weighing 100 lb. The stone must be of exceptional quality, and costs 500 gp. Sculpting the body requires a DC 13 Craft (stonemasonry) skill check.
----Creating a temple gargoyle has the following requirements: Craft Construct, create water, bless water, lesser planar ally, magic circle against evil, caster must be good and at least 9th level; Price: 15,000 gp, Cost: 8,000 gp + 600 XP

----Though more rare, temples devoted to gods of non-good alignments sometimes craft temple gargoyles. Such creations have their special qualities and attacks shifted to reflect their new alignment. For example, a chaotic temple gargoyle would smite law, enjoy the protection of a magic circle against law, and could use its water spout attack thrice per day to damage undead or lawful outsiders.


Tunnel Guardian
Medium Magical Beast
Hit Dice: 8d8+24 (60 hp)
Initiative: +3
Speed: 20 ft. (4 squares), climb 20 ft., swim 20 ft.
Armor Class: 19 (+3 Dex , +6 natural), touch 13, flat-footed 16
Base Attack/Grapple: +8/+10
Attack: Gore +10 melee (1d8+3) or 4 spikes +11 ranged (1d6+2/19-20)
Full Attack: Gore +10 melee (1d8+3) or 4 spikes +11 ranged (1d6+2/19-20)
Space/Reach: 5 ft./5 ft.
Special Attacks: Spikes
Special Qualities: Darkvision 60 ft., independent eyes, repulsion field, true seeing.
Saves: Fort +9, Ref +9, Will +3
Abilities: Str 14, Dex 16, Con 16, Int 4, Wis 13, Cha 14
Skills: Climb +10, Escape Artist +4, Hide +6*, Listen +2, Move Silently +5, Search +5, Spot +11, Swim +10
Feats: Ability Focus (repulsion), Point Blank Shot, Precise Shot
Environment: Underground
Organization: Solitary or pack (2-5)
Challenge Rating: 6
Treasure: Standard
Alignment: Always neutral
Advancement: 9-12 HD (Medium), 13-18 HD (Large)
Level Adjustment: -1

Blue and scaly, this creature resembles a man-sized chameleon, complete with three horns and a pair of bulbous eyes. Its tail ends in a thick knot of sharp spikes.

----Tunnel guardians are reptilian carnivore often tamed by Underdark residents to protect sensitive passageways. They are valued highly for their ability to not only defend an area, but to literally prevent passage by any creature.
----The tunnel guardian is a solitary hunter, using its magical abilities to corner rats, bats, or any small mammals it comes across. They will often cling motionless to a cave wall, waiting for potential food to pass by before activating its repulsion. Tunnel guardians have few natural predators; those beasts that would normally prey on the chameleon-like creatures have difficulty overcoming their inherent defenses. They prefer wet caves, often lairing near subterranean lakes and streams.
----Very few tunnel guardians still live wild in the Underdark, however, as their value as a sentry is so great that most are raised in captivity now. They are widely tamed by troglodytes, though they have also been encountered in the service of duergar, hobgoblins, and kuo-toa. Some have even been trained to wear special barding, to greater protect the investment their trainers have made in them.
----Tunnel guardians cannot speak, but can be trained to understand simple phrases in one language, usually Undercommon.

----Tunnel guardians only use their tail spikes for protection against larger creatures, in which case they use the repulsion to keep enemies at bay while pelting them with spikes. When trained to protect a location, they are often paired with regular guards armed with bows or other missile weapons. The guardian is commanded to keep the repulsion effect at full strength while the archers shoot.
----Independent Eyes (Ex):Tunnel guardians' eyes can look in opposite directions simultaneously. They cannot be flanked.
----Repulsion (Su): Tunnel guardians radiate a constant magical field that acts as similar to the repulsion spell (caster level 11th). Whenever a creature attempts to move towards the tunnel guardian, they must make a Will save (DC 18; this save is Charisma-based). If they fail, they cannot move towards the tunnel guardian this round, though they may move in another direction or take any other action. They may attempt to move towards the guardian on future rounds, though they will need to make a new save to do so. Once a creature successfully saves against a tunnel guardian's repulsion, they are unaffected by the repulsion of that particular creature for a period of one hour.
----The guardian may enlarge or reduce the radius of the repulsion as a free action during its turn, up to a maximum radius of 110 feet. A tunnel guardian is always unaffected by the repulsion of another tunnel guardian.
----Spikes (Ex): A tunnel guardian can let loose a volley of four sharp tail spikes as a standard action (make an attack roll for each one). This attack has a range of 220 feet with no range increment. All targets must be within 30 feet of each other. In any 24-hour period, a tunnel guardian can only launch one volley of four spikes for every 4 Hit Dice it possesses.
----True Seeing (Su): Tunnel guardians can see through illusions easily; they operate as if under a continuous true seeing spell.
----Skills: Tunnel guardians gains a +15 racial bonus to its Hide skill checks in an underground environment. They have a +8 racial bonus to all Search and Spot skill checks.
----The tunnel guardian receives a +8 racial bonus on Climb checks and can always choose to take 10 on Climb checks, even if rushed or threatened.
----The tunnel guardian also receives 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 a run action while swimming, provided it swims in a straight line.

Training a Tunnel Guardian
----Training a tunnel guardian requires a successful Handle Animal skill check (DC 26 for a young specimen; DC 30 for an adult). A tunnel guardian matures in two years. Their eggs or young are worth 9000 gp on the open market, while professional trainers charge an additional 3000 gp to train them.
----In addition to learning tricks that can be taught to any creature, tunnel guardians can be trained to raise or lower their repulsion effect on command (Handle Animal skill check DC 20), to alter the radius of the field on command (DC 25), or to make a special noise whenever it sees an invisible creature or an illusion (DC 30), though it cannot tell its owner exactly where the deception magic is being used.

Tunnel Master
Large Outsider (Augmented Magical Beast) (Evil)
Hit Dice: 18d8+108 (189 hp)
Initiative: +4
Speed: 20 ft. (4 squares), climb 20 ft., fly 20 ft. (average), swim 20 ft.
Armor Class: 22 (+4 Dex , +9 natural, -1 size), touch 13, flat-footed 18
Base Attack/Grapple: +18/+30
Attack: Gore +23 melee (2d6+8) or 4 spikes +21 ranged (2d6+8/19-20)
Full Attack: Gore +23 melee (2d6+8) and 2 claws +21 melee (1d6+4) and bite +21 melee (1d8+4); or 4 spikes +21 ranged (2d6+8/19-20)
Space/Reach: 10 ft./10 ft.
Special Attacks: Smite good, spell-like abilities, spikes
Special Qualities: Damage reduction 10/magic, darkvision 60 ft., immunity to poison, independent eyes, repulsion field, resistance (acid, cold, fire, and electricity) 10, spell resistance 28, true seeing.
Saves: Fort +17, Ref +15, Will +9
Abilities: Str 26, Dex 18, Con 22, Int 8, Wis 13, Cha 16
Skills: Concentration +11, Climb +21, Escape Artist +9, Hide +21*, Listen +22, Move Silently +25, Search +23, Sense Motive +12, Spot +30, Swim +21
Feats: Ability Focus (repulsion), Cleave, Improved Natural Attack (spikes), Improved Precise Shot, Iron Will, Multiattack, Point Blank Shot, Power Attack, Precise Shot, Quicken Spell-Like Ability (unholy aura).
Environment: Underground
Organization: Solitary
Challenge Rating: 13
Treasure: Double standard
Alignment: Always lawful evil
Advancement: -
Level Adjustment: -1

This creature appears to be a giant blood-red chameleon, but an sinister resolve burns in its bulbous eyes. Deadly black spikes grow from its tail and a trio of jagged horns adorns its scaly head.

----In the deepest subterranean kingdoms, there are tales of massive tunnel guardians, almost as large as the passages they defend. Few, however, know that the blood of a demon runs in their veins. Intelligent and deadly, the tunnel masters are used as free roaming guardians by the minions of the most powerful demon lords.
----The tunnel master is identical to the tunnel guardian, except as listed above and described here:
----Repulsion (Su): A tunnel master's repulsion effect has a Will save DC of 24, reflecting the creature's greater Hit Dice and higher Charisma score.
----Smite Good (Su): Once per day, a tunnel master may make a normal melee attack to deal extra damage equal to its Hit Dice (in this case, +18) against a good foe.
----Spell Like-Abilities (Sp): 3/day: darkness, poison (DC 22), unholy aura (DC 21). 1/day: blasphemy, contagion (DC 16), desecrate, horrid wilting (DC 21), summon monster IX (fiends only), unhallow, unholy blight (DC 17). Caster level 18th and all save DCs are Charisma-based.

Looking Back...
I don't really have anything to say about the monsters. I mean, they're monsters. They work well enough. The only interesting thing is that an official version of a piranha swarm appeared in Stormwrack, and it was almost exactly the same except for being one point of Challenge Rating higher.