Faerie Folk Information
Although IPMA stories have their own take based upon the research of IPMA agents about Faerie Folk, a good starting point are the following websites, containing links to and descriptions of types of faeries and dragons both:
Troll Brother Faerie Folk
The following races and characters have been identified so far in the Troll Brother Series.
Of the troll "Race" the mountain trolls are generally the second largest and live in caves, usually began as natural caves but typical expanded, mined and excavated to the point that many tunnels in one given mountain or range lead to the same root cavern. This root cavern is typically large enough to hold anywhere from 100 to 1000 mountain trolls in various constructions of wood and iron. Often the root cavern will have side tunnels which to not exit to the earth surface but serve as smaller caverns for dining, sleeping, refining, nursery, etc.
Mountain Trolls, as with all trolls, are "hatched" from stones that have been hand selected by the troll matriarchs and infused with magic. A typical mountain troll will live to nearly 1000 years, though some are known to live much longer, and of course wartime, disease or other causes do tend to shorten the average lifespan of a mountain troll. They grow to well over ten feet tall, though the females are generally human or human-child sized and proportioned, and males are almost always large.
As trolls grow larger, they tend to lose communication skills and mental capacity. Because females tend to be hatched for more intellectual and nurturing purposes in their society and males are generally hatched for defense, building and labor the females naturally tend to retain their fairly high degree of intellect, but males do not. Hence the impression for a couple millennia among humans that trolls are savage or stupid and violent. This has been a source of human-troll warfare in the past. Of course, the growth and purpose of each troll is dependent upon the stone selection and variables do occur.
Each Mountain Troll clan tends to be lead by two individuals determined by a sort of democratic election to be King and Queen. However, each clan in the various Mountain Troll root caverns or cities spread throughout the world may approach the question of leadership differently, and there have been times when a king or queen is deposed.
Goblins are smallish creatures, standing between about three-and-a-half feet tall to as tall as five feet in some cases. Compared to Mountain Trolls they are relatively short lived and relatively non-intellectual. The travel, work and hunt in packs and are often said to move and to think like ants. That of course implies there is some sort of leader or guide motivating them. On their own, each goblin is really only concerned for their immediate welfare, including food and water, sleep and little else. However, when functioning as a group they are more aggressive about territory and they covet the trappings of other societies, human and faerie folk alike. They idolize gold and gems. They are able to form rude armors and weapons and they do have some skill in domesticating or at least controlling various animals.
For the most part, goblins in the last many centuries have retreated to the mountain tops, and are said to live in dens and small caves, almost never actually constructing a building other than to control animals or form the aforementioned clothing or armor, etc. Their thick hide and limited nervous system seems to make possible, and even encourage a life among very cold climates and high elevations, though in ancient faerie histories it is clear they can and will live in any climate as is necessary to supply their basic needs.
As far as the Rocky Mountain goblins discovered in Troll Brother 1, it has since been determined that they are being led by a goblin queen who may or may not be fully goblin herself. The few glimpses of her have so far suggested she has fairer skin and more human proportions, but that she may be wielding lesser forms of magic to control her ranks.
Goblins are grey and green-skinned and look roughly toad-ish, particularly because they move hunched-over most of the time. Their hair is typical black or quite dark and their eyes tend to be yellowed. This may or may not be due to a plague-level disease among them, or jaundice caused by too little excursion into the sun.
Due to their inability to wield magic, even according to the old texts, Goblins are considered by many other fey folk to not be entirely faerie. There is some question about this, and even the IPMA (Institute for the Preservation of Magical Artifacts) has declined to make a determination at this time, in part because their lineage is unknown at this time. It is assumed they descended from elves, but if so something must have happened to have corrupted both their bodies and intellect as well as their ability to sense and use magic.