The Faeries by William Allingham

William Allingham was an Irish poet who lived from 1824 to 1889. This poem in particular has played a bigger role in pop culture than you would think (if you thought there wasn't one)

From Wikipedia: The opening lines from Allingham's poem The Fairies was quoted by the character of The Tinker near the beginning of the movie Willy Wonka & the Chocolate Factory, as well as in Mike Mignola's comic book short story Hellboy: The Corpse, plus the 1973 horror film Don't Look in the Basement. This same poem was quoted in Andre Norton’s 1990 science fiction novel Dare To Go A-Hunting.

The Faeries

Up the airy mountains
Down the rushy Glen,
We dare not go a-hunting
For fear of little men;
Wee folk, good folk
Trooping all together;
Green jacket, red cap,
And a white owl's feather.

Down along the rocky shore
Some make their home,
They live on crispy pancakes
Of yellow-tide foam;
Some in the reeds
Of the black mountain-lake
With frogs for their watch-dogs,
All night awake.

High on the hill-top
The old King sits;
He is now so old and gray
He's nigh lost his wits.
With a bridge of white mist
Columbkill he crosses,
On his stately journeys
From Slieveleague to Rosses;
Or going up with music,
On cold starry nights,
To sup with the Queen,
Of the gay Northern Lights.

They stole little Bridget,

For seven years long;
When she came down again
All her friends were gone.
They took her lightly back
Between the night and morrow;
They thought she was fast asleep,
But she was dead with sorrow.
They have kept her ever since
Deep within the lake
On a bed of flag leaves
Watching till she wake.

By the craggy hill-side
Through the mosses bare,
They have planted thorn trees
For pleasure here and there.
Is any man so daring
As dig them up in spite?
He shall find the thornies
In his bed at night.

Up the airy mountains
Down the rushy glen,
We dare not go a-hunting
For fear of little men;
Wee folk, good folk
Trooping all together;
Green jacket, red cap,
And a white owl's feather.

Here's a video of someone narrating the poem.