"Oh, a wonderful horse is the Fly-Away Horse
Perhaps you have seen him before;
Perhaps, while you slept, his shadow has swept
Through the moonlight that floats on the floor.
For it's only at night, when the stars twinkle bright,
That the Fly-Away Horse, with a neigh
And a pull at his rein and a toss of his mane,
Is up on his heels and away!"
from The Fly-away horse
by Eugene Field