Shee

Shee are unintelligent fey beasts, though "unintelligent" might be a deceptive term. While Shee lack awareness or a concept of "Self" as humans would understand it, they are capable of displays of intelligence that no mere beast would generally be capable of, including being capable of understanding the concept of debt (debt is, of course, a central drive for fairies regardless of intelligence). As such a Shee that was rescued by a human might very well seek to repay the kindness even if the Shee was otherwise destructive.

While all fairies are capable of entering into contracts, the complex social contract of civilized society are beyond the abilities of a Shee to understand. As such, Shee are not allowed in the City of the Fireflies under normal circumstances, though sometimes "tamed Shee" might be allowed as long as they have a human or elf who will take responsibility for them.

Most of the time when Shee are brought up, however, it is because a hostile Shee is terrorizing a human or a civlized area. Like all fairies, Shee are prideful, and in dumb animals this will generally take the form of territorial behavior or a desire to rearrange one's environment to suit them. Shee often wander into the City of the Fireflies through Crossings. A Knight's primary duty is to keep civilians safe from the attacks of Shee, evil Fairies, and evil Warlocks, but Shee attacks are the most frequent of these duties to come up.

Classification of Shee
Fairies don't follow the same laws of evolution and natural selection that mundane animals do, and their form may often be influenced by the environment they find themselves in and the events that occur in their lives, sometimes to dramatic degrees. These traits can often be passed down to young. Fairies could therefore be said to be shaped by a dramatic variety of Lamarckian evolution. As such ideas like "species" aren't entirely appropriate to Shee. That said, while there are many "unique" Shee with no others of their own kind, even these can generally produce offspring, which may or may not resemble them in obvious ways.

That said, some forms of Shee do occur often enough that they are treated as species rather than individuals. These include such creatures as the Cait Sidhe and the Sul Caileach.

Most monsters known to humans through folklore are, in one form or another, based on Shee, even if in folklore they were not considered fairies. For example, The yeti is a primate-like Shee creature, and the chupacabra is another.