Omnimental (CR 15)

Gargantuan Elemental (Air, Earth, Extraplanar, Fire, and Water)
Alignment: Usually neutral
Initiative: +4; Senses: blindsight 120 ft., darkvision 60 ft., Listen +37, and Spot +37
Languages: Aquan, Auran, Ignan, and Terran

AC: 32 (-4 size, +26 natural), touch 6, flat-footed 32
Hit Dice: 32d8+288 (432 hp); DR: 10/-
Fort +27, Ref +18, Will +12
Speed: 50 ft., fly 50 ft. perfect), swim 50 ft.
Space: 20 ft./20 ft.
Base Attack +24; Grapple +48
Attack: Slam +32 melee or elemental ball +20 ranged
Full Attack: 2 slams +32 melee or elemental ball +20 ranged
Damage: Slam 2d8+12 plus 2d8 fire and 1d8 electricity, elemental ball 4d6+12 plus 1d8 fire
Special Attacks/Actions: Death birth, elemental ball
Abilities: Str 35, Dex 10, Con 28, Int 10, Wis 11, Cha 11
Special Qualities: elemental traits, immunity to electricity and fire, vulnerability to cold
Feats: Alertness; Awesome Blow; Blind-fight; Cleave; Combat Reflexes; Great Cleave; Improved Bull Rush; Improved Initiative; Improved Natural Attack (slam); Iron Will; Power Attack
Skills: Listen +37, Spot +37, and Swim +20
Advancement: 33-48 HD (Gargantuan); 49-64 HD (Colossal)
Climate/Terrain: Elemental Plane of Fire
Organization: Solitary
Treasure/Possessions: None

Source: Monster Manual III

Death Birth (Su): When an omnimental reaches 0 hit points, it bursts into its component elemental parts, creating four 16 HD Huge elementals, one each of air, earth, fire, and water. (Defeating these Huge elementals earns no additional experience points. Their XP value is accounted for in the Challenge Rating of the omnimental.)

Elemental Ball (Ex): As a standard action, an omnimental can detach part of itself to create a clod of flaming earth that it can fling at an opponent up to 100 feet away. Using this ability reduces the omnimental's current hit points by 10.

Skills: An omnimental 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.

An impressive combatant in all kinds of terrain, an omnimental can devastate a battlefield. Its size and reach enable it to attack many foes at a distance. Its elemental ball attack grants the creature further options at long distances.

Air Subtype

This subtype usually is used for elementals and outsiders with a connection to the Elemental Plane Air. Air creatures always have fly speeds and usually have perfect maneuverability (see the section on Movement).

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.

Fire Subtype

A creature with the fire subtype has immunity to fire. It has vulnerability to cold, which means it takes half again as much (+50%) damage as normal from cold, regardless of whether a saving throw is allowed, or if the save is a success or failure.

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.