An important note for this write up. These pixies are different from the variety of pixies that Lex-Kat has created.
Appearance and Physical Traits:
Pixies are, of course, very small. The average pixie stands at about five inches tall with only a little variance. Not only are they tiny, but proportionally they are much slimmer. Narrow hips, waist, shoulders, and limbs are common among both males and females. This contributes to them being rather willowy in stature. They very rarely have much in the way of significant muscle mass.
Each and every pixie has some manner of insect like wings. Most often they look like the wings of butterflies and moths though they are not limited to designs, colours, and shapes that regular moths and butterflies are limited to. Their colour can vary wildly, often being very bright. Furthermore, they have antenna that stick out of their forehead, just below the hair line. They vary as much as their wings do. Their purpose is to feel movements in the air, often for predators.
Skin, hair, and eye colour have no real constant. It depends on parents' traits as well as location, among other factors. Hair is typically natural colours such as browns, blonds, and reds. Eyes are generally similar, but have a larger range than humans. More exotic colours are possible, but are as rare as they are prized. Skin colour typically ranged from white to lighter browns.
Other traits include somewhat large eyes as well as longer, more nimble fingers. Pixies have hollow bones in order for them to fly more easily.
Also, all pixies glow faintly. This glow can be suppressed with a thought from the pixie in question. As an added note, pixies will not often let their hair grow past their shoulders. Much longer and it would interfere with their wings. Often times it's kept rather short. A pixie cut, if you will.
Skills and Abilities:
All pixies have the ability to fly. It's a a magical ability inherent to them, but the wings still play an important role and are necessary. Their flight tends to be very quick and darting, and they are capable of hovering.
Pixies' eyes are far superiour to humans. Firstly they allow for much greater light absorption, giving pixies excellent night vision, though it does leave them more sensitive to very bright lights. Secondly, pixies are capable of seeing colours more vividly and are able to see far more colours than most.
A pixie's antenna are very sensitive, to the point where they can pick up on most movement around them by feeling the air movements. This in combination with their fast reflexes makes them very hard to catch by surprise.
Pixies are able to produce a magical substance called pixie dust. It's produced in the body through purely natural means as a liquid. It can be released from the pours in the pixie's hands. When it makes contact with the air is becomes a powdery substance. The pixie can only release so much before the body has to make more.
The actual magic of the pixie dust is, on the other hand, very supernatural. What it does is entirely based on what the user desires it to do. There are limitations, however. The pixie dust can only manipulate and change what already exists and whatever the effect is, it is always temporary barring outside interference. The greater the effect, the more pixie dust is needed to apply it, and thus it takes longer to apply. That said, there are a truly massive amount of possibilities.
Birth, Life, and Death:
Pixies are born through regular sexual reproduction. Childbirth is rather easy on pixie mothers. They often bear many children during their lifespans.
The beginning of a pixie's development it rather fast, twice as fast as a human in the first three years. They are fully capable of walking in the first six months, and flying in the first year. From that point on the pace slows, though they reach full physical maturity my the age of sixteen.
Pixies have long lifespans for something so small. On average they will live slightly longer than humans, often to ninety. As tehy near the end of their lifespans, they do grow slower and weaker, but are still very spry when compared to what one would expect of the elderly. They show few outward signs of their age.
Pixies reproduce through sexual reproduction. Most often with another pixie, but not always. More on that later. Pixies are very fertile and usually have many children over their lifetime. Not only that, but their pregnancies take about three months and are very easy on the mother. It's very common for a pixie to give birth to twins. In fact, there are more often twins than single babies.
Due to pixies being able to reduce the size of another living being, it is possible for them to mate with other species. Pixies have an overwhelming tendency to very closely match the species of the mother in the pair. If the mother is a pixie, the child will, for all intents and purposes, be a pixie that draws traits form the father. Similarly, if the mother is the other species, the child will be as well, drawing traits from the pixie father. The length of the pregnancy is determined by the mother's species.
Dryads: (Only semi-canon)
On occasion, a flower from a tree may catch the attention of a pixie, and if that pixie is a male, he may choose to mate with the flower. This, on occasion, can result in a dryad being born from the tree a few weeks later. This is not strictly sexual reproduction, more of a magical process.
Pixies, on average, are very fond of bright lights and colours. This can be attributed to a factor in attracting mates. Other pixies glow and have brightly coloured wings.
As I flesh this out and come up with more information, it will be updated.