Encounters: The Lowerdark (Underground, Desolate)
Delver (CR 9)
Alignment: Usually Neutral
Initiative: +5 (+1 Dex, +4 Improved Initiative); Senses: darkvision 60 ft., tremorsense 60 ft., Listen +20, and Spot +20
Languages: Terran and Undercommon
AC: 24 (-2 size, +1 Dex, +15 natural), touch 9, flat-footed 23
Hit Dice: 15d8+78 (145 hp)
Fort +12, Ref +6, Will +11
Speed: 30 ft., burrow 10 ft.
Space: 15 ft./10 ft.
Base Attack +11; Grapple +27
Attack: Slam +17 melee
Full Attack: 2 slams +17 melee
Damage: Slam 1d6+8 plus 2d6 acid
Special Attacks: Corrosive Slime
Abilities: Str 27, Dex 13, Con 21, Int 14, Wis 14, Cha 12
Special Qualities: immunity to acid, stone shape
Feats: Alertness; Blind-fight; Great Fortitude; Improved Initiative; Power Attack; Toughness
Skills: Knowledge (dungeoneering) +14, Knowledge (nature) +4, Listen +20, Move Silently +17, Spot +20, and Survival +14 (+16 underground)
Advancement: 16-30 HD (Huge); 31-45 (Gargantuan)
Climate/Terrain: Any underground
Source: Monster Manual
Corrosive Slime (Ex); Delvers produce a mucus-like slime that contains a highly corrosive substance. The slime is particularly effective against stone.
A delver's mere touch deals 2d6 points of damage to organic creatures or objects. Against metallic creatures or objects, delver's slime deals 4d8 points of damage, and against stony creatures (including earth elementals) or objects it deals 8d10 points of damage. A slam attack by a delver leaves a patch of slime that deals 2d6 points of damage on contact and another 2d6 points damage in each of the next 2-rounds. A large quantity (at least a quart) of water or weak acid, such as vinegar, washes off the slime.
An opponent's armor and clothing dissolve and become useless immediately unless the wearer succeeds at a Reflex save (DC 22). Weapons that strike a delver also dissolve immediately unless the wielder succeeds at a Reflex save (DC 22).
Creatures attacking the delver with natural weapons take damage from the slime each time their attacks hit unless they succeed at Reflex save (DC 22).
Tremorsense (Ex): A delver can automatically sense the location of anything within 60 feet that is in contact with the ground.
Stone Shape (Ex): A delver can alter its slime to temporarily soften stone instead of dissolving it. Once every 10 minutes, a delver can soften and shape up to 25 cubic feet of stone, as stone shape cast by a 15th-level druid.
Delvers prefer to fight from their tunnels, which they use to protect their flanks while lashing out with their flippers.
A delver expecting trouble may honeycomb an area with tunnels, leaving most closed with layers of stone 1 or 2 inches thick. The delver can quickly dissolve the stone cover and pop up attack unexpectedly.