Nixies are sentient plants that look after their less intelligent brethren and serve as nature's verdant watchers. Normally, they begin their existence as bodiless spirits of nature, and Druids often turn to them for information and license to act through magic. These spirits typically have no way to manipulate the physical world directly, but a magic-user (usually a druid during their initiation ritual) can grow a special plant body for one of these spirits, providing it with a home to animate in exchange for the Nixie's services and loyalty to the Druid. Nixies have a wide range of appearances, and it is said that no two Nixies look alike. Some walk on legs that resemble intertwined tendrils, while others have scattered eyes that dot a thick mushroom cap. Some are composed of soggy green algae, while others have (leaf)wings and can fly by floating in the air. Generally, however, a Nixie is never more than 1 or 1.5 feet tall and almost always has a negligible weight, less than 2 or 3 kilograms. They cannot speak, but they can communicate through gestures or empathy, and they possess a sharp and refined intelligence, albeit underdeveloped.
Nixies do not fear death as many other creatures do because they know that if they fall, their spirits will simply return to the natural world and can be called upon to inhabit a new body in the future. As a Nixie's body dies, the magic animating it unravels in a burst of life energy that infuses the surrounding area and quickens the growth of any plants nearby. Some Nixies even voluntarily discorporate to save the lives of ailing plants, knowing that their sacrifice may mean the continuation of countless otherwise helpless flora. Regardless of how a Nixie dies, leaving the body traumatizes the spirit, and the Nixie retains only faint memories of past corporeal existences.