Gloomy, gloomy was the night,
And eerie was the way,
As fair Jenny in her green mantle
To Miles Cross she did gae.
At the mirk and midnight hour
She heard the bridles sing,
She was as glad at that
As any earthly thing.
First she let the black pass by,
And syne she let the brown,
But quickly she ran to the milk-white steed,
And pu'd the rider down.
Sae weel she minded what he did say,
And young Tam Lin did win,
Syne covered him wi her green mantle,
As blythe's a bird in spring.
From the Ballad of Tam Lin (Child 39A). I'm currently re-reading Diana Wynne Jones's Fire and Hemlock, a modern re-telling of the Tam Lin tale as a fantasy novel.