Naiads (The Chronicles of Narnia)

Naiads, are River Nymphs who lived in the rivers and streams of Narnia.

Biography
They were most commonly found in the Great River of Narnia. They are human-like in appearance, and are spiritually tied to the waters of Narnia. No physical description is given, but are depicted as pretty women dressed in gowns of aquatic colors, most commonly in blue, and sometimes wearing crowns of rushes around their heads.

The Magician's Nephew
At the birth of Narnia, they are described as rising out of the river, along with the River God. They are mentioned as being train bearers for Narnia's first female monarch, Queen Helen, at her coronation.

The Lion, the Witch and the Wardrobe
When the White Witch conquered Narnia, she placed the entire land under a spell of constant winter, thus freezing all the water. It seems most likely the Naiads spent most of the Age of Winter frozen, unable to do anything, until Aslan freed them. During the Winter Revolution, they were among Aslan's followers at the Stone Table, fighting alongside their fellow Narnians against the White Witch.

Prince Caspian
When the Telmarines conquered Narnia, thus beginning the Telmarine Age of Narnia, the Naiads and the River Gods went into a form of deep sleep. While they slept, the Telmarines built a large bridge over the river, which inadvertently kept the River God, and probably the rest of the Naiads as well, imprisoned.

Eventually, they fought against the Telmarines when they were awoken by Aslan to help fight against the Telmarine army, thus beginning the reign of Caspian X.