Pagan Themes in an English folk song

This old English folk song seems very pagan and has some clear parallels in old pagan mythology. It is the story of two magical people, originally gods, usually wizards in the song, who can change their shape. One, often a blacksmith, is pursuing the other, often a virgin girl, who attempts to escape by transforming into animals and things, but he pursues by also transforming. It is a bit un PC!

https://www.youtube.com/watch?v=iicvIlDOgmY