In the lore of Connacht, Ireland, Caer ("yew berry") is a beautiful jinni maiden living in the shape-shifted form of a swan; it was adorned with necklaces of golden chains and bells.
When the handsome God of Love, Angus, saw the beautiful Caer in a dream, he fell so deeply in love with her he immediately fell ill upon waking because he was not with her.
In one version of the myth Angus sought out Caer's father, Ethal, one of the Tuatha De Danann, and asked permission to marry her; it was given on the provision the young suitor could pick out his beloved from a flock of swans. Angus agreed and on the selected day went to the lake where he immediately knew his beloved Caer from all other swans. As he called out her name he transformed into a swan himself; together, the couple flew away.
In an alternative version of the myth Angus had to have his father, the Dagda, imprison Ethal to persuade him to give Caer marriage. In a final version, it was Caer who lured Angus to the lake in order to transform him into a swan so they could be together, forever.