“The wren, the wren, the king of all birds. Saint Stephen’s day he got caught in the firs. So it’s up with the kettle and down with the pan. Won’t you give me a penny to bury the wren.”
Old Irish poem.
My dad used to say this on Saint Stephen’s day, which is December 26. The custom was, when I was growing up, on Saint Stephen’s night people would come dressed in disguise to your door and sing for money. We called them, “the mummers.”
Here are two more sites that discuss the tradition in more detail: