Monolith, Ooze (CR 17)

Gargantuan Elemental (Earth, Extraplanar, and Water)
Alignment: Neutral
Initiative: +6 (Dex); Senses: darkvision 60 ft., Listen +41, and Spot +41
Languages: Aquan, Terran

AC: 27 (-4 size, +6 Dex, +15 natural), touch 12, flat-footed 21; Dodge
Hit Dice: 36d8+252 (414 hp); DR: 15/-
Fort +27, Ref +20, Will +16
Speed: 20 ft., swim 50 ft.
Space: 20 ft./20 ft.
Base Attack +27; Grapple +53
Attack: 2 slams +37 melee
Damage: 2 slams 6d8+14/19-20 plus 4d6 acid
Special Attacks/Actions: heat metal
Abilities: Str 38, Dex 22, Con 25, Int 12, Wis 15, Cha 17
Special Qualities: elemental traits (Immune critical hits, flanking, paralysis, petrification, poison, sleep effects, sneak attacks, stunning), vulnerability to cold
Feats: Awesome Blow, Cleave, Combat Reflexes, Dodge, Great Cleave, Improved Bull Rush, Improved Critical (slam), Improved Natural Attack (slam), Improved Sunder, Iron Will, Lightning Reflexes, Power Attack, Weapon Focus (slam)
Skills: Diplomacy +5, Intimidate +16, Jump +27, Listen +41, Sense Motive +15, Spot +41, and Swim +22
Advancement: 37-54 HD (Gargantuan)
Climate/Terrain: Elemental Plane of Earth and Elemental Plane of Water
Organization: Solitary
Treasure/Possessions: None

Source: Dragon #347

Acid (Ex): An ooze monolith secretes a digestive acid that dissolves organic material and metals quickly but does not affect stone. Any melee hit deals acid damage, and the armor and clothing of an opponent dissolve and become useless immediately unless the opponent succeeds on DC 35 Reflex saves. A metal or wooden weapon that strikes an ooze monolith also dissolves immediately unless its wielder succeeds on a DC 35 Reflex save. The save DCs are Constitution-based. The ooze monolith's acidic touch deals 35 points of acid damage per round to wooden or metal objects, but the ooze must remain in contact with the object for 1 full round to deal this damage.

Skills: An ooze monolith has 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.

Earth Subtype

This subtype usually is used for elementals and 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.

Extraplanar Subtype

A subtype applied to any creature when it is on a plane other than its native plane. A creature that travels the planes can gain or lose this subtype as it goes from plane to plane. This book assumes that encounters with creatures take place on the Material Plane, and every creature whose native plane is not the Material Plane has the extraplanar subtype (but would not have when on its home plane). An extraplanar creatures usually has a home plane mentioned in its description. These home planes are taken from the Great Wheel cosmology of the D&D game (see Chapter 5 of the Dungeon Master's Guide). If your campaign uses a different cosmology, you will need to assign different home planes to extraplanar creatures.

Creatures not labeled as extraplanar are natives of the Material Plane, and they gain the extraplanar subtype if they leave the Material Plane. No creature has the extraplanar subtype when it is on a transitive plane; the transitive planes in the D&D cosmology are the Astral Plane, the Ethereal Plane, and the Plane of Shadow.

Water Subtype

This subtype usually is used for elementals and 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 usually can breathe air as well.