Changelings

Overview
There are five distinct groups of changelings, each one referred to as a 'Hive'. Each Hive has at its head a Queen - a powerful creature that is rarely, if ever seen by non-changelings. Queens are fully sentient, very intelligent, and by necessity often very charismatic.

The Queen is then attended by a number of changelings often referred to as 'Courtiers' (as they form her 'court'). They are powerful in their own right, and have had sentience bestowed upon them by their Queen. This makes them largely independent creatures, though they are always psychically linked to each other and to the Queen of their hive.

Below the Courtiers is the rest of the hive - a myriad creatures with a wide range of capabilities. Some of them are almost sentient themselves, while most of them are not sentient at all, entirely controlled by the will of the Hive. All of them, however, are all connected to a great hierarchical psychic network with the Queen at its heart. The purpose of this network is twofold - firstly, of course, to communicate back and forth with orders and reports, but secondly to carry the flow of 'love', the energy that Changelings feed on, upwards through the network, and eventually to their Queen.

The Queen consumes this energy, and uses it to further the goals of the Hive. The larger her hive, the greater the flow, and the more powerful she becomes.

Hives
The five known hives are listed here alphabetically:

The Chrysalis Hive
The Chrysalis Hive is led by Queen Chrysalis, its colouration bluish greens. Probably the largest known hive, it is characterised by aggression and militant behaviour. Chrysalis is the most openly ambitious known Queen, masterminding grand plots to take control of large chunks of the world. This lack of subtlety often acts against her though, and her campaign is currently stalling after a thorough defeat at Canterlot.

The Hagfish Hive
The Hagfish Hive is led by Queen Myxine, its colouration light blues. It is a relatively small hive, living along the coastal regions of the world. With the oceans of the world being so dangerous, they don't get large quantities of love, so Myxine keeps the hive small and agile. Myxine herself is strongly motivated by survival, and is a calculating and logical Queen.

The Honeycomb Hive
The Honeycomb Hive is led by Queen Ambrosia, its colouration vibrant yellows. The hive can most commonly be found in hot, humid environments like rainforests, though can be found in many temperate forests besides. Their behaviour is not particularly aggressive, Ambrosia seemingly content with what power she has now, and there are even reports of peaceful contact with the hive. Ambrosia acts in a somewhat childlike manner, intensely inquisitive with strong psychotic tendencies.

The Miasma Hive
The Miasma Hive is led by Queen Miasma, its colouration deep purples and pinks. Its name is appropriate, as by and large they occupy the most offensively noxious environments - sewers and dumps being a favourite. They consequently are attracted to civilisation, and often conceal themselves within (or ideally, underneath) large settlements. Miasma is vain and aloof, considering herself the most beautiful changeling (if not creature in general) in the world. Those encountering her often find it difficult to breathe - not so much because of the foul stench of her hive, but more because of the cloying, choking, sweet perfumes that she is perpetually covered in - or the smoke from the incense burners she surrounds herself with.

The Nekropolis Hive
The Nekropolis Hive is led by Queen Calliphora, its colouration pale whites. One of the more recently reported hives, its existence has still not been officially confirmed. Reportedly, they occupy graveyards, catacombs, tombs and the like. They are nocturnal, and exhibit bizarre behaviours that range from the seemingly random to the ritualistic. They do not aggressively expand, but do react to intruders violently. Calliphora is unpredictable, her motives mysterious and her behaviour unsettling.

The Lucid Hive
The Lucid Hive originally splintered off from the Chrysalis Hive due to a catastrophic disruption of the psychic network. The effected changelings were transformed, taking on bright pastel hues and a crystalline shimmer. All of the members of this new hive are sentient, and are overwhelmingly Good-aligned. They follow Thorax, an otherwise normal changeling that was the origin of the disruption, though he holds no mental control over them. As a side-effect of the splintering, they have no psychic network connecting them - on the other hand, however, they also seem to no longer need to consume Love to survive. The Hive is somewhat reclusive, being extremely new, and are receiving some support from Equestria.

Here's a link to raw Changeling stat blocks:

Changeling stat blocks

Mindlink (Ex)
Changelings share a telepathic bond with other members of their hive that brings mutual enhancements to perception. As long as a changeling is within telepathic range of at least one other hive-mate, it gains a +4 racial bonus on initiative checks and perception checks. If at least one changeling disbelieves an illusion, all changelings within its telepathic range are also considered to disbelieve that illusion. If one changeling is aware of characters, all other hive mates within range of its telepathy are also aware of those characters.

All changelings have a telepathy range. Two changelings can communicate if they are closer to eachother than the sum of their respective telepathy ranges. Thus a changeling with a 200ft telepathy range and one with a 30ft telepathy range can communicate up to 230ft away. This ability can 'chain' indefinitely. As long as a chain of 'connected' changelings can be traced from one hive member to another, they are considered to be in direct contact for all intents and purposes.

Drone
Changelings with this quality are entirely dependent upon their hive for sustenance and direction, and will do nothing without orders from above. They follow instructions explicitly and are incapable of complex strategy or tactics without direct supervision. If they lose contact with a Node or higher they will attempt to follow their most recent order to the best of their ability, though if attacked they will retaliate. Drones do not require sustenance if they are in contact with a Node or higher, but cannot sustain themselves by any other means and will perish after their hit die in days without contact.

Node
Changelings with this quality have some semblance of independence from their hive. In the event that contact with a Greater Node or higher is lost, they will attempt to complete whatever orders they were last given. They are capable of comprehending and carrying out simple missions and are often charged with scouting, short-term infiltration or leading squads of drones in battle, and will intelligently use their own abilities and the abilities of any available subordinates to complete objectives. They lack initiative however, and will rarely deviate from their explicit mission parameters.

Greater Node
Changelings with this quality have a greater degree of independence. They are intelligent and imaginative, and are skilled strategists, tacticians and infiltrators. Greater Node infiltrators are exceedingly difficult to detect, Commanders can successfully lead long and eventful campaigns, and so on.

Nexus
Completely sentient, highly intelligent, always have character levels, most powerful changelings besides the Queen

Queen
If you encounter one of these, ya done goofed.

“Love Drain”
Forced: A Changeling in its natural form can drain ‘Love’ from a pinned or helpless opponent. If it chooses to do so, it causes 1d4 points of Charisma damage. The Changeling heals 5 hit points or gains 5 temporary hit points for 1 hour (up to a maximum number of temporary hit points equal to its full normal hit points) each round it drains love.

Ambient: For every hour that a changeling is in the presence of a sentient non-changeling with an attitude of ‘Helpful’ towards them, they heal 5 hit points or gain 5 temporary hit points (up to a maximum number of temporary hit points equal to its full normal hit points). These temporary hit points persist for one hour after losing contact with the target (Or after their attitude falls below ‘helpful’). For every eight hours in contact, the target suffers 1d4 Charisma damage.