Undine Dragons are named for the water spirits with which they share territory. They have close relationships with these spirits, and are able to communicate with them. In exchange for protection and respect of their mutual freshwater homes, laid eggs are often protected by a blessing. This blessing stays with the dragon into adulthood, and with it they gain potent magical abilities. Sometimes when an Undine Dragon becomes very upset, the ground at their feet may frost over or begin to steam. They have also been observed to manipulate water directly, rerouting raindrops or creating puddles from groundwater. Undine Dragons always live near forest pools, streams, or waterfalls. Both genders take equal part in the raising of young and are very good parents—though they may not remain mated after the offspring are grown.

Dragons are highly-intelligent reptilian creatures that—from a human perspective, at least—appear to live forever. Many different varieties of dragon exist, each with their own unique qualities, habitats, and behavior. Adolescence in dragons is usually marked by the growth of a hatchling’s wings, although not all breeds of dragons grow wings and some breeds have other traits that indicate the beginning of maturation. In Galsreim, dragons and humans coexist peacefully.

Once there was a pristine mountaintop lake that was home to an entire underwater civilization occupied solely by water sprites and Undine Dragons. It all came to an end when a volcano that was believed to be dormant unexpectedly erupted once again. The volcanic ashfall horribly contaminated the lake, and the entire civilization was fatally poisoned. Only a very young water sprite named Cerato and a newly-hatched Undine hatchling managed to escape the deadly ashfall when Cerato's parents forced the pair through a hidden underground channel that led to safety. The underground channel eventually led them to a small pond within a willow grove. Now orphaned and alone in an unknown place, Cerato and her Undine companion, whom Cerato named after the man who created the first water sprite through alchemy, forged an unbreakable bond, both knowing that their survival depended on staying together. Even after they reached adulthood, Cerato and Philippus Aureolus remained inseparable friends.