Warrior

(From 3.5e Monster Manual I - 2003):

Formians hail from the plane of Mechanus. They seek to colonize all that they see and incorporate all living things into their hive as workers. 

Expansionist in the extreme, formians are dedicated to spreading their colonies until they have taken over everything and their order is unquestioned. To further this end, they attack all other creatures, usually to put them to work building and expanding cities. Formians maintain these “conscripted” workers as well as those mentally dominated by the power of their taskmasters. 

A formian resembles a cross between an ant and a centaur. All formians are covered in a brownish-red carapace; size and appearance differs for each variety.

Formians build fabulous hive-cities in which hundreds of the creatures dwell. They are born into their station, with no ability to progress. Workers obey orders given by warriors, myrmarchs, or the queen. Warriors carry out the will of their myrmarch commanders or the queen. Myrmarchs take orders only from the queen herself, although they have different ranks depending on services rendered. These are not positions of power but of prestige. The most prestigious of the myrmarchs guard the queen. Taskmasters are equal in rank to warriors but seldom interact with other formians.

The Warrior: Formian warriors exist only to fight. 

Warriors rank only slightly above workers. They communicate through the hive mind to convey battle plans and make reports to their commanders. They cannot speak otherwise. A warrior is about is about 5 feet long and about 4-1/2 feet high at the front. It weighs about 180 pounds.

Combat: Warriors are wicked combatants, using claws, bite, and a poisonous sting all at once. Through the hive mind, they attack with coordinated and extremely efficient tactics. 

A formian warrior’s natural weapons, as well as any weapons it wields, are treated as lawful-aligned for the purpose of overcoming damage reduction. 

Poison (Ex): Injury, Fortitude DC 14, initial and secondary damage 1d6 Str. The save DC is Constitution-based.

(From Planescape: Planes of Law Monstrous Supplement - 1995):

"Had mine eyes ever beheld such beauty? To think, all fashioned by a bug!"

- Unknown traveler upon reaching a formian city

Native to Arcadia, formians are also called centaur ants. As their moniker indicates, they appear to he uprightwalking ants, but their sentience is that of warmblooded creatures as opposed to insects. They’ve always inhabited Arcadia, and sages say they always will. Though formians found on the Prime make war on each other, Arcadian formians of different hives have learned to live together peaceably. 

Similar to true ants, there are three basic types of formians: the worker, the wamor, and the myrmarch. (A fourth type, the queen, is extremely rare.) Unlike ants, formians’ waists are flexible; thus, they often move with only four legs, their heads and thoraces raised. Their forelegs are jointed at the wrist and have three opposing claws, which they can use to manipulate objects and to attack. Formians come in various subdued colors, which serve no function other than to indicate their cities of  origin.

Formians of warrior level and higher can communicate with humans, though their version of common sounds more like eerie chittering. They communicate with one another in their own speech, which is incomprehensible to most other beings.

The Warrior: The warrior is the size of a pony, and its claws are indicative of its capability to defend the hive.

Combat: Warriors attack with their mandibles, two forelegs, and a stinger that injects poison, causing 2d4 points of damage (save versus poison or suffer -2 to attack rolls for ld6 turns).