In Celtic lore, the spirit guardian of the rivers and lakes is often referred to as the Selkie. These mystical beings, typically depicted as seals, possess the ability to transform into humans, reflecting themes of transformation and duality. Selkies are associated with the water's mysterious nature and represent a connection to the changing tides of life. In tales, they often engage in romances with humans, highlighting desires, loss, and the longing for freedom. Such legends emphasize the spiritual significance of water and its role in the cultural and environmental identity of the Celtic people.