Nymphs are the reason the forest, water works, air ways, and anything that nature has given the world is still around. They are creatures that are extremely in tuned with nature. There are many different types, but the main types you see these days are water, forest, air, and fire nymphs. They are naturally playful creatures, usually mysterious and not looking for company but enjoys it when it comes. They live like humans, but usually near the element that they can "control". So say they are a water nymph, they most likely live pretty close to a large body of water. forest nymphs usually have cottages near or in forests. So on and so forth. Now they do have one ability, a one time only ability that they can use on anyone. It's called "the gift". An ability that can be used on anyone to give them any number of things. But if can only be used once, you hear, once. Nymphs are what many would call a hippie, especially the forest kind. Water Nymphs are the "save the whales" kind of type. Some have wings, mainly forest and air nymphs though. Easily hidden at will.
Nymphs are immortal, but not in the normal way. When Nymphs create a child the child will age quickly, usually looking as if they are just about 7 years old only a single year after being born. By the time they hit their twenties aging goes to a complete halt and they will then live for ever to keep the earth alive.
Now since they are such pure creatures anything that might contaminate them is bad for them, smog and the such kills their lungs, toxic water seems to burn the skin of water nymphs as does acid rain. Forest nymphs are extremely sensitive to heat, fire nymphs can't stand cold temperatures and air nymphs seem to know when the air isn't pure. It causes them great sadness to see their forest, waters and the like in such pain.