Formian Observer (CR 11)

Medium Outsider (Extraplanar and lawful)
Alignment: Always lawful neutral
Initiative: +6; Senses: all-around vision, Listen +16, and Spot +16
Languages: Telepathy 250 ft.

AC: 17 (-2 Dex, +5 natural), touch 12, flat-footed 15
Hit Dice: 9d8+18 (58 hp)
Fort +8, Ref +8, Will +10
Speed: 40 ft.
Space: 5 ft./5 ft.
Base Attack +9; Grapple +10
Attack: Sting +10 melee
Full Attack: Sting +10 melee
Damage: Sting 2d4+1
Special Attacks/Actions: Poison, spell-like abilities
Abilities: Str 12, Dex 15, Con 14, Int 18, Wis 19, Cha 17
Special Qualities: hive mind, evaluation, immunities, outsider traits, resistances, SR 23
Feats: Alertness; Improved Initiative; Track
Skills: Climb +11, Craft (any one) +13, Diplomacy +15, Hide +12, Listen +16, Move Silently +11, Search +13, Sense Motive +14, Spot +16, and Survival +13 (+15 following tracks)
Advancement: 10-13 HD (Medium-size); 13-27 HD (Large)
Climate/Terrain: Any land and underground (Mechanus)
Organization: Team (2-4) or platoon (2-4 plus 7-18 workers and 6-11 warriors)
Treasure/Possessions: -

Source: Fiend Folio

Hive Mind (Ex): All formians within 50 miles of queen are in constant communication. If one is aware of a particular danger they all are. If one in a group is not flat-footed none of them are. No formian in a group is considered flanked unless all of them are.

Immunities (Ex): Formians have cold, petrification, and poison immunity.

Outsider Traits: Formians have darkvision (60-foot range), and they cannot be raised or resurrected (though a wish or miracle spell can restore life).

Resistances (Ex): All formians have fire, electricity, and sonic resistance 20.

Observers do their best to avoid getting into melee. They remain in the background so that they can deduce the behavior and tactics of the intruders for the benefit of the other formians to exploit. In addition to using their evaluation ability observers try to determine how many and what kind of magic the intruders might possess.

Observers can be summoned using a summon monster IX spell.

Poison (Ex): An observer delivers its poison (Fort DC 16 negates) with each successful sting attack. Initial and secondary damage are the same (1d6 Int).

Spell-like Abilities: At will - charm monster, clairaudience/clairvoyance, detect chaos, detect magic, detect thoughts, see invisibility, true seeing. Caster level 12th; save DC 13 + spell level.

All-Around Vision (Ex): Observers are exceptionally alert and circumspect. Their double set of unblinking eyes grants them a +4 racial bonus on Spot and Search checks, and they cannot be flanked.

Evaluation (Ex): The incredible minds of observers evaluate and break down the strengths and weaknesses of enemies in mere moments.

For each full round of combat that an observer can visually see a single opponent (magical means, including clairvoyance, do not work), each formian in contact with the hive mind gains a +1 insight bonus on attack rolls against that opponent. This effect is cumulative for each round of combat and does not have a limit.

The effect lasts until the observer is killed, knocked unconscious, blinded, or cannot see the target for 1 full round. This bonus begins again as soon as the observer sees them again, starting at +1 per round.

The bonus does not improve if multiple observers are watching the same target. Other formians can process the information from any number of observers watching multiple targets.

Telepathy (Su): An observer can communicate telepathically with any creature within 250 feet that has a language.

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.

Lawful Subtype

A subtype usually applied only to outsiders native to the lawful-aligned Outer Planes. Most creatures that have this subtype also have lawful alignments; however, if their alignments change, they still retain the subtype. Any effect that depends on alignment affects a creature with this subtype as if the creature has a lawful alignment, no matter what its alignment actually is. The creature also suffers effects according to its actual alignment. A creature with the lawful subtype overcomes damage reduction as if its natural weapons and any weapons it wields were lawful-aligned (see Damage Reduction).