Aengus:

Celtic god of love and youth. Son of the Dagda and the wife of Elcmar, believed to be the goddess Boann.
From the valley of the River Boyne, Aengus was said to have dreamed of a beautiful maiden, for whom he searched all Ireland. He eventually found her, named Caer, chained to 150 maidens who were destined to turn into swans at the feast of Samhain (November 1). Aengus transformed himself into a swan and was so united with Caer, who followed him back to his palace at New Grange.