Update 12/29 - Added Worg stats from MM.  Changed Markesa's armor so that it is protection from arrows.
Added Strength and magic bonus to Icar's Great Sword.
Changed the Goblins in 18c from 2nd levl to 1st level.  This will still be a very difficult encounter.  Almost killed my players, I had changed the Worg's when I got the MM and didn't notice how tough they were.

Update 1/19/01 - Changed link to Scott Greene's web sight for the Boggle conversion.

Icar Level 7 Fighter
CR 7, HD 7d10+14, HP 60; Init +2; Spd 20ft, AC 17 (+7 Half Plate); Atks +11/+9 melee (2d6+7, 19-20, +1 Great Sword), SV Fort +7, Ref +7, Will +6; Str 17, Int 14, Wis 15, Dex 16, Con 15, Cha 16;
skills:  Jump +0, Listen +3, Escape Artist +1, Speak Language 5, Climb +6, Ride +13, Handle Animal +5, Bluff +4;
Feats:  Blind-Fight(x3 -- so he can fight without penalties even though he is blind), Ambidexterity, Dodge, Iron Will, Lightning Reflexes, Mounted Combat
Note: he has a Ring of Elemental Fire Resistance Major

Executioner Ogre note: bumped his str up to avg for an Ogre, Gave him the Improved disarm feat as per description in module and bumped up his Int so that it was min for Improved Disarm.
CR 2; Large Giant(9' tall), HD 4d8+8; HP 25; Init +1(dex), Spd 30 ft; AC 18 (-1 size, +1 dex, +5 natural, +3 hide); Atk +8 melee (Bastard Sword 1d10+5, 19-20), SV Fort +6, Ref +2, Will +2; Str 21; Int 13; Wis 12; Dex 12; Con 14; Cha 6; Feats:  Weapon Focus(Bastard Sword),  Expertise, Improved Disarm

Gulyet Goblin  Wizard 3/ Cleric 2  note put his +1 into Int so he can cast 2nd level spells
CR 5, HD 3d4+3 + 2d8+2; HP 19; Init +0; Spd 20; AC 16 (+1 Size, +1 Chain Shirt ); Atk +4 melee (1d8+1 x2, +1 Morningstar);  SV Fort +4, Ref +1, Will +6; Str 10, Int 12, Wis 12, Dex 10, Con 12, Cha 4;
skills: +2 Move Silently, +3 Knowledge (Monster Lore), +7 Concentration, +1 Climb, +0 Tumble, +2 Knowledge(Arcane), +5 Profession (Slaver);
Feats: Silent Spell, Skill Focus (Monster Lore)
Wizard Spells (20% arcane spell failure)4,3,1    4, 3+1
O Level(4):  Light, Prestidigitation, Open/Close, Daze
1st Level(3): Hypnotism, Message, Shield
2nd Level(1): Invisibility
Cleric Spells  War & Fire Domains
O Level(4): Read Magic(x2), Mending
1st Level(3+1): Burning Hands, Endure Elements(Heat), Cure Light Wounds, Obscuring Mist

Winter Wolf CR 3; Medium Animal(6ft long); HD 6d8+12; HP 42; Init +4(Dex); Spd 50 ft; AC: 16 (+4 Dex, +2 natural); Atk: +9 melee (1d6+1 Bite); SA trip; SQ scent; AL N; SV Fort +9, Ref +11, Will +5; Str 13, Dex 20, Con 15, Int 2, Wis 12, Cha 6; Skills:  Hide +5, Listen +6, Move Silently +6, Spot +4, Wilderness Lore +4; Feats:  Weapon Finess(Bite).
    SA - Trip (Ex):  A wolf that makes a successful bite attack can attempt to trip its opponent as a free action without making a touch attack or provoking an attack of opportunity.  If the attempt is unsuccessful, the victim cannot react to trip the wolf.
    SQ - Scent:  Wolves can detect opponents within 30 ft by smell.  If it is downwind, the range increases to 60 ft; if upwind, the range decreases to 15 ft.  Wolves can also follow a trail with a successful Wisdom check.  Fresh trails are DC 10 for this purpose and increase by 2 for every hour the trail ages.
Note: I used the Wolves in Dead of Winter as the basis for these stats.

Hobgoblin Patrol CR 1/2; Medium Humanoid (6ft tall); HD 1d8+1; hp 6 each; Init +1(dex), Spd 30 ft; AC 15 (+1 Dex, +3 studded leather, +1 small shield); Atks +0 melee (1d8, longsword) or +1 ranged (1d6, javelin) or +1 ranged (d6 x3 short bow); AL LE; SV Fort +3, Ref +1, Will +0, Str 11, Dex 13, Con 13, Int 10, Wis 10, Cha 10.
    skills: Hide +1, Listen +4, Spot +4.  Hobgoblins receive +4 racial bonus to Move Silently checks.  Feats:  Alertness
    Leader:  As above except where noted:  CR 2; 1st level Fighter; HD 1d8+3 + 1d10+3; hp 15; AC Atks +5 melee (1d8 +4, longsword) or +4 javelin (1d6+4); SV Fort +7, Ref +3, Will +2; Str 18, Dex 16, Con 16; skills as above plus Climb +8, Swim +4, Open Lock +4, Jump +5; Feats:  Ambidexterity, Blind-Fight;
Note:  I just rolled his stats randomly and added the +2 Dex and +2 Con as per DMG.

Hobgoblin Shamen  note:  I just made him a Cleric level 5 since that is the minimum level to cast level 3 spells.
As Hobgoblin except as noted.  CR 6; HD 1d8 +2  +5d8+10, hp 38, AC 13 (-1 Dex, +3 studded leather, +1 small shield); Atks +4 melee (1d6+1, light mace), SV Fort: +8, Ref 0, Will +7;  Str 13, Dex 9, Con 15, Int 9, Wis 16, Cha 10,  skills: spell craft +5, Concentration +3, Scry +0, Feats: Run, Silent Spell, Domains: Fire and Magic,
Spells: 0 lvl(5): Detect Magic(x2), Inflict Minor Wounds, Read Magic, Virtue; 1st level(4+1):  Burning Hands(domain), Cure light wounds, Remove Fear, Magic Stone, Command;   2nd level(3+1):  Produce Flame(domain), Augury, Speak with Animals, Bull's Strength; 3rd level(2+1):  Dispel Magic(domain), Bestow Curse, Invisible Purge.

War Dogs  note: Monster Manual isn't out yet so just gonna us the conversion document and guess
CR 1; AC: 14; MV: 30; HD 2d8+2; HP 11 each; Atks +3 (2d4 bite)

Carnivorous Apes
CR 3; AC: 14; MV 30; HD 5d8; HP: 23 each; Atks: +5/+5/+5 d4 claw, d4 claw, d8 bite

Gnolls
CR 1; Medium Humanoid (7 1/2 feet tall); HD 2d8+2; HP 11; Init +0; Spd 20 ft (scale mail); AC 17 (+1 natural, +4 scale mail, +2 large shield); Atks +3 melee (1d8 + 2 battleaxe); SQ darkvision 60 ft; AL CE; SV Fort +4, Ref +0, Will +0; Str 15, Dex 10, Con 13, Int 8, Wis 1, Cha 8; skills:  Listen +3, Spot +3.  Feats: Power Attack
Gnoll Leader:  as per Gnoll + 1st level Fighter  CR 2; HD 2d8+3 + 1d10+3; HP 27; Init +2; AC 19 (as above +2 dex);  Atks: +7 (1d8 +6 battleaxe or 1d6+6 Nunchaku); SV Fort +8, Ref +2, Will +1; skills: Jump +10; Feats: Alertness, Exotic Weapon Proficiency (Nunchaku)

Escaped Slave
CR 1/2; Human; AC 20; MV: 30; HP 6; Atks +0

Key to The Hill Fort

2d. Room over the Gate.
DC 15 Spot check to get the feeling of being watched.

2e. East Guard Post.
Use a DC 20 will save instead of the save vs. spells.

2f.  East Walkway.
Haunt CR 4; AC 20; MV 30'; HD 5d8; HP 23; Atks +5 melee (ignores armor for to hit determination, drains 2 points of Dex per hit); AL LG.  Everything else is as per module.  Note:  to get the XP the characters should help the Haunt out.

4.  Winch Room
Each lock is DC 20.

5. Outer Courtyard:
Anhkheg CR 3; Large Beast; AC 19; MV 30'/20' burrow; HD 3d10+9; HP 28; Atks +6 melee (2d6+7 bite); Face/Reach 5 ft. by 10 ft./5 ft.;  SA  Improved grab, acid, spit acid; SQ Tremorsense; Saves: Fort +6, Ref +3, Will +2; Str 21, Dex 10, Con 17, Int 1, Wis 13, Cha 6; Skills: Listen +4  Note: See the end of the document for a full description.

12. The Parade Ground:
See the end of the document for stats on a Boggle.

13. The Inner Courtyard:
Oak Door, DC 20 lock; DC 25 strength check to break it down (two characters can work at once , use one roll but add the STR bonuses for each character, always at least +1 for the second character).

17a.  The Bear:
DC 20 Reflex save or take 1d6 damage from the 'bear'.
Again DC 20 Reflex save for the rotating wall.
This is a CR 1 trap.

21b. Trapped Corridor:
DC 25 Reflex save to avoid falling in pit.
DC 10 Search check to find the pit; No way to disable it other than triggering it.
DC 20 Search check to find the nearly invisible wire.

23 Store Room
DC 20 lock.  DC 15 to break door down.

25.  Room of Slaves.
Cloaker  CR 5, AC 17 body, 19 tail; MV 10'/40' (fly); HD 6d8; HP 33; Atks +6 melee (fly and envelop victim, if success then bites for 1d4 + AC of victim -20 automatic per round and victim cannot attack), +6 melee (1d6 tail flail).  Int 16
All the spell like abilities are at 6th level of use.
Cloak of Protection +2 is now a Cloak of Resistance +2.

35.  The Kitchen
Wearboars CR4, AC 16, Damage reduction +1/Silver or 5 hit points; MV 30'; HD 5d8+2; HP 27, 23, 21; Atks +6 melee (gore for 2d6).

Dungeon Level

Dire Rats Small Animal; HD: 1d8+1; HP 5; Init +3 (dex); Spd 40 ft, climb 20ft; AC 15 (+1 size, +3 Dex, +1 natural); Atk: +4 melee (bite 1d4; SA: Disease; SQ: Scent; Fort: +3, Ref +5, Will +3; Str 10, Dex 17, Con 12, Int 1, Wis 12, Cha 4; Skills: Climb +11, Hide +11, Move Silently +6; Feats:  Weapon Finess(Bite)
    Leader CR 1/2; AC 13; MV 30; HD 1; HP 7; Atks +1 melee (bite 1d4).

Baby Boggle CR 1; AC 16(+1 size); MV 30'; HD 2d8; HP 14; Atks +2/+2/+2 melee (1 claw, 1 claw, 1 bite).

Goblin CR 1/4; HD 1d8; HP 4; Initiative +1(Dex); Spd 30'; AC 15 (+1 size, +1 dex, +3 studded leather); Atks +0 melee (1d6-1 x3 Half Spear); SQ Darkvision 60'; Fort +0, Ref +3, Will +0; Str 8, Dex 13, Con 11, Int 10, Wis 11, Cha 8; skills: Hide +6, Listen +3, Move Silently +5, Spot +3; Feats Alertness.

Witchdoctor & patrol  see Goblin above and Gulyet at the beginning.

Wolves CR 1; Medium Animal (6 ft long); HD 2d8+4; HP 13; Init +2(dex); Spd 50'; AC 14 (+2 dex, +2 natural); Atk +3 melee (1d6+1 bite); SA trip; SQ scent; AL N; SV Fort +5; Ref +5; Will +1; Str 13; Dex 15; Con 15; Int 2; Wis 12; Cha 6. Skills:  Hide +3, Listen +6, Move Silently +4, Spot +4, Wilderness Lore +4; Feats:  Weapon Finess(Bite).
    SA - Trip (Ex):  A wolf that makes a successful bite attack can attempt to trip its opponent as a free action without making a touch attack or provoking an attack of opportunity.  If the attempt is unsuccessful, the victim cannot react to trip the wolf.
    SQ - Scent:  Wolves can detect opponents within 30 ft by smell.  If it is downwind, the range increases to 60 ft; if upwind, the range decreases to 15 ft.  Wolves can also follow a trail with a successful Wisdom check.  Fresh trails are DC 10 for this purpose and increase by 2 for every hour the trail ages.
Note: I used the Wolves in Dead of Winter stats.

Haunt
Haunt CR 4; AC 20; MV 30'; HD 5d8; HP 27; Atks +5 melee (ignores armor for to hit determination, drains 2 points of Dex per hit); AL LG.  Everything else is as per module.  Note:  to get the XP the characters should help the Haunt out.

3. Abandoned Guardroom.
DC 10 Search to find the Concealed door.

4. Parlor
Giant Spiders CR 3; AC 16; HD 4+4; HP 26, 20; Atks +5 melee (2d4 + poison bite); Hide +8; SQ Poison bite drains 1d4 Str initially and character must make another save 1 minute later or lose 1d6 Str, DC 16(I upped it by 2 because the DMG only listed medium sized spiders) Fort Save to negate.  A character with Str of 0 falls to the ground and is helpless.
DC 20 Reflex save to avoid the web trap.

7. Log Trap.
Covered Pit Trap CR1; DC 20 Reflex save avoids; Search DC 20; Disable Device DC 20.
Log Trap CR 2; DC 20 Reflex save if climbing the wall.

8. Boggle Lair
See Boggle entry at end.  Hp 21, 24

12. Torture Chamber
DC 20 reflex save to avoid the chandelier oil.
16 Goblins CR 1/4; HD 1d8; HP 6; Initiative +1(Dex); Spd 30'; AC 15 (+1 size, +1 dex, +3 studded leather); Atks +0 melee (shortsword 1d6-1), +2 ranged (sling 1d4-1); SQ Darkvision 60'; Fort +0, Ref +3, Will +0; Str 8, Dex 13, Con 11, Int 10, Wis 11, Cha 8; skills: Hide +6, Listen +3, Move Silently +5, Spot +3; Feats Alertness.

a. Observation Post
Bugbears CR 2; AC 14 (+3 Natural, +1 Dex); MV 30'; HD 3d8+3; HP 17, 19; Atks +5 melee (1d10+2 x3 Halberd); SV Fort +1, Ref +3, Will +1; Str 14; Dex 12; Con 12; Int 10; Wis 10; Cha 8; Skills Climb +2, Hide +2, Listen +1,  Move Silently +2, Spot +1; Feats:  Alertness, Weapon Proficiency

b. Walled Up Alcove.
Wolf CR 1; Medium Animal (6 ft long); HD 2d8+4; HP 13; Init +2(dex); Spd 50'; AC 14 (+2 dex, +2 natural); Atk +4 melee (1d6 bite); SA trip; SQ scent; AL N; SV Fort +5; Ref +5; Will +1; Str 10( -3 disease); Dex 15; Con 15; Int 2; Wis 12; Cha 6. Skills:  Hide +3, Listen +6, Move Silently +4, Spot +4, Wilderness Lore +4; Feats:  Weapon Finess(Bite).
    SA - Trip (Ex):  A wolf that makes a successful bite attack can attempt to trip its opponent as a free action without making a touch attack or provoking an attack of opportunity.  If the attempt is unsuccessful, the victim cannot react to trip the wolf.
    SQ - Scent:  Wolves can detect opponents within 30 ft by smell.  If it is downwind, the range increases to 60 ft; if upwind, the range decreases to 15 ft.  Wolves can also follow a trail with a successful Wisdom check.  Fresh trails are DC 10 for this purpose and increase by 2 for every hour the trail ages.
This wolf is infected with the Red Ache disease (DMG p. 75; DC 15; 1d3 day incubation; 1d6 Str).

c. Worg Dens
Worg Medium Size Magical Beast, HD 4d0+8, HP 30, Init +2(dex), Spd 50 ft, AC 14 (+2 Dex, +2 natural), Atk Bite +7 melee (1d6+4), SA Trip as free action when hit, SQ Scent, SV Fort +6, Ref +6, Will +3, Str 17, Dex 15, Con 15, Int 6, Wis 14, Cha 10, Skills Hide +7, Listen +9, Move Silently +7, Spot +9, Wilderness Lore +2, Feats Alertness, CR 2.

14. The Chasm.
Jumping from pinnacle to pinnacle is a DC 15 Balance check (+5 for slippery already added in).  CR 1 obstacle.

16. Beehives
CR 1 obstacle.

18a. The Corridor.
The goblin must make a ranged attack and has a +7 to hit.

18c. Elite Goblin Barracks
Warning this is an EL 9.9.  You may want to reduce the numbers to 6 & 6, which still gives a 8.7
9 Goblin Fighter Lvl 1; CR 2; HD 1d10+2; HP 8, leader 12; Initiative +2(Dex); Spd 30'; AC 16 (+1 size, +2 dex, +3 studded leather); Atks +2 melee (1d6+1 x3 light lance, x2 when on Worg), +2 (1d8+1 morning star); SQ Darkvision 60'; Fort +5, Ref +2, Will +0; Str 13, Dex 14, Con 14, Int 11, Wis 10, Cha 7; skills: Intuit Direction +3, Handle Animal -1, Hide +6, Listen +3, Swim +3, Move Silently +5, Spot +3; Feats Alertness
Note: the leader has a +1 Battleaxe (1d8+2 melee damage for him).  I changed the +1 Halberd to a battleaxe since a goblin can't wield a Halberd).

9 Worgs Medium Size Magical Beast, HD 4d10+8, HP 30, Init +2(dex), Spd 50 ft, AC 14 (+2 Dex, +2 natural), Atk Bite +7 melee (1d6+4), SA Trip as free action when hit, SQ Scent, SV Fort +6, Ref +6, Will +3, Str 17, Dex 15, Con 15, Int 6, Wis 14, Cha 10, Skills Hide +7, Listen +9, Move Silently +7, Spot +9, Wilderness Lore +2, Feats Alertness, CR 2.

21. Watchworg Post
Worgs Medium Size Magical Beast, HD 4d10+8, HP 30, Init +2(dex), Spd 50 ft, AC 14 (+2 Dex, +2 natural), Atk Bite +7 melee (1d6+4), SA Trip as free action when hit, SQ Scent, SV Fort +6, Ref +6, Will +3, Str 17, Dex 15, Con 15, Int 6, Wis 14, Cha 10, Skills Hide +7, Listen +9, Move Silently +7, Spot +9, Wilderness Lore +2, Feats Alertness, CR 2.

22. Markessa's Laboratory
Markessa Wizard 5/Fighter 1
CR 6; Wiz 5/Ftr 1; HD 5d4+15 + 1d10+3; HP 40; Init +4; Spd 30 ft; AC  18 (+4 for magic +1 studded leather , with permanent Protection from Arrows, + 4 for dex); Atks +8/+8 melee (1d6+3, +1 shortsword of speed), or +7 ranged (1d4+2 dart); SV Fort +8, Ref +5, Will +5; Str 14, Dex 18, Con 17, Int 16, Wis 12, Cha 14.
skills: Knowledge(nature) +11, Tumble +7, Forgery +4, Craft (Dissection) +12, Spellcraft + 4, Profession(Botonist) +9, Alchemy +11, Concentration +4, Swim +2, Knowledge (Arcane) +4, Disguise +2.5
Feats: Brew Potion, Endurance, Great Fortitude, Spell Focus(Evocation), Weapon Finess(shortsword)
15% arcane spell failure from her armor, +3 Spell DC from Intelligence
0 level: Resistance, Prestidigitation, Ghost Sound, Open/Close
1st Level:  Magic Missile, Protection from Good, Shocking Grasp, Endure Elements
2nd Level:  Darkness, Scare, Locate Object
3rd Level:  Lightning Bolt (+2 DC), Halt Undead

Warning Owlbears are considerably tougher in 3e.  You may want to use only one Owlbear. This is an EL 8.7 with 2 Owlbears and an EL 8.1 with 1 Owlbear.
2 Owlbears  CR 4; Large beast (8' tall); HD 5d10+20; HP 47; Init +1(Dex); Spd 30'; AC 15(-1 size, +1 Dex, +5 natural); Atks +7 melee(1d6+5 [x2], claws), +2 melee (1d8+2 bite); Face 5 ft x 10 ft; SA improved grab; SQ scent; AL CE; SV Fort +8, Ref +5, Will +2; Str 21, Dex 12, Con 19, Int 5, Wis 12, Cha 10; Skills Listen +8, Spot +7;
SA -- Improved Grab (Ex): If an owlbear hits with a claw attack, it deals normal damage and attempts to start a grapple as a free action without provoking an attack of opportunity.  No touch attack is required to use this ability, and tiny and small creatures suffer no size penalty.  This ability works only against creatures at least one size category smaller than the owlbear.
SQ -- Scent: Owlbears can detect opponents within 30 ft by smell.  If it is downward, the range increases to 60'; if upwind, the range decreases to 15'.  Scent does not allow the Owlbear to pinpoint the location of an opponent, just the general area.  Once it gets within 5', however, it can determine a specific location.  Strong scents (smoke) carry twice as far, and overpowering scents (skunk musk) carry three times as far  Owlbears can also follow a trail with successful Wisdom check.  Fresh trails are DC 10 for this purpose and increase by 2 for every hour the trail ages.

13 Goblins CR 1/4; HD 1d8; HP 8; Initiative +1(Dex); Spd 30'; AC 15 (+1 size, +1 dex, +3 studded leather); Atks +0 melee (shortsword 1d6-1), +2 ranged (shortsword 1d6); SQ Darkvision 60'; Fort +0, Ref +3, Will +0; Str 8, Dex 13, Con 11, Int 10, Wis 11, Cha 8; skills: Hide +6, Listen +3, Move Silently +5, Spot +3; Feats Alertness.

Special Attacks:
Bite: If a boggle hits with both claws, it  latches onto the opponent's body and bites at it's flesh. This attack automatically deals an additional 1d4+1 points of damage.
Elongation: A boggle can stretch its body and limbs up to twice its original size thus increasing it's reach to 10 ft.

Special Qualities:
Oil Secretion (Ex.): Acts as a permanent oil of slipperiness (DMG, pg. 191) for the boggle. This gives the boggle a +30 on all escape artist skill checks. A boggle may excrete it onto the floor (full round action) in a 5x5 square. Anyone entering the square must make a Reflex save vs. DC 15 or slip and fall. A successful save allows movement at half speed across the surface. Those remaining in the area covered with this oil must make a new save each round or slip and fall. The boggle can move freely across a surface covered with this oil. This oil is non-flammable. A boggle will try and steal (pick pockets) any one item from a fallen character.
Scent (Ex.): Boggles may detect creatures by smell up to 30 ft away. The range
increases to 60 ft. if the creature is upwind, and decreases to 15 ft. if the creature is downwind.
Dimension Door (Ex.): At will, as the spell though the range is limited to 30 ft.
Resist Fire (Ex.): Due to the oily secretion in their skin, they absorb the first 30 points of fire damage per round.
Spider Climb (Ex.): At will, as the spell.
Damage Reduction (Ex.): Due to the oily secretion from their skin, all slashing and bludgeoning weapons deal -1 points of damage per attack.

Boggles are 3-foot tall, roughly humanoid creatures. Their rubbery skin
varies in color from blackish-blue to dark gray. Boggles have large bulbous
heads and the rest of their body parts are disproportionate and vary from
individual to individual (arms of different lengths, spindly legs, etc.)
 

Ankheg  from the monster manual preview http://www.wizards.com/dnd/DnD_MM_Final_001.asp.
The assorted sizes of ankheg are gone, replaced by the Advancement range entry. Also note the change in the ankheg’s type.
Large Beast
Hit Dice: 3d10+9 (25 hp)
Initiative: +0
Speed: 30 ft., burrow 20 ft.
AC: 18 (–1 size, +9 natural)
Attacks: Bite +6 melee
Damage: Bite 2d6+7
Face/Reach: 5 ft. by 10 ft./5 ft.
Special Attacks: Improved grab, acid, spit acid
Special Qualities: Tremorsense
Saves: Fort +6, Ref +3, Will +2
Abilities: Str 21, Dex 10, Con 17, Int 1, Wis 13, Cha 6
Skills: Listen +4
Climate/Terrain: Temperate and warm plains, forest, and underground
Organization: Solitary or cluster (2–4)
Challenge Rating: 3
Treasure: None
Alignment: Always neutral
Advancement: 4 HD (Large); 5–9 HD (Huge)

The ankheg is a burrowing monster with a taste for fresh meat. One bite of its powerful mandibles can snap a small tree.

An ankheg looks like a huge segmented worm or caterpillar with six slender legs, each ending in a sharp claw. A tough chitinous shell, usually brown or yellow, covers its entire body. It has glistening black eyes and two sensitive antennae. An ankheg is about 10 feet long and weighs about 800 pounds.

An ankheg uses its legs and mandibles to dig a winding tunnel up to 40 feet below the surface in the rich soil of forests or farmlands. The tunnel is about 5 feet tall and wide, and from 60 to 150 feet long. The hollowed ends of the tunnel serve as temporary lairs for sleeping, eating, or hibernating.

Ankhegs can eat decayed organic matter but prefer fresh meat. Though a hungry ankheg might kill a farmer, the creature is quite beneficial to farmland. Its tunnel system laces the soil with passages for air and water, while its wastes add rich nutrients.

Combat

An ankheg usually lies 5 to 10 feet below the surface until its antennae detect the approach of prey. It then burrows up to attack. (Treat this as a charge.)

Clusters of ankhegs share the same territory but do not cooperate. If several attack, each tries to grab a different foe. If there aren’t enough targets, two might grab the same creature in a tug of war.

Improved Grab (Ex): To use this ability, the ankheg must hit with its bite attack. If it gets a hold, it deals automatic bite damage each round the hold is maintained. If the ankheg is damaged after grabbing its prey, it retreats backward down its tunnel at burrowing speed, dragging the victim with it.

Acid (Ex): Acidic enzymes drip from an ankheg’s mouth each round it maintains a hold. It automatically deals 1d4 points of acid damage each round in addition to bite damage.

 Spit Acid (Ex): Stream of acid 5 feet high, 5 feet wide, and 30 feet long, once every 6 hours; damage 4d4, Reflex half DC 14. One such attack depletes the ankheg’s acid supply for 6 hours. It cannot spit acid or deal acid damage during this time.

Ankhegs do not use this ability unless they are desperate or frustrated. They most often spit acid when reduced to fewer than half their hit points or when they have not successfully grabbed an opponent.

Tremorsense (Ex): Ankhegs can automatically sense the location of anything within 60 feet that is in contact with the ground.