Undine

Undines are a category of imaginary elemental beings associated with water, first named in the alchemical writings of Paracelsus. Similar creatures are found in classical literature, particularly Ovid's Metamorphoses. 

They are similar to water Nymphs, Naiads, Nereids and Oceanids, but are exclusively blue skinned and do not take complete human form. They generally live in Aqua Towns and can work as general workers to doctors and philosophers. 

• Half-Undine are extremely rare. 
• Both male and female.