The Unseen Playmate by Robert Louis Stevenson
When children are playing alone on the green,
In comes the playmate that never was seen.
When children are happy and lonely and good,
The Friend of the Children comes out of the wood.
Nobody heard him, and nobody saw,
His is a picture you never could draw,
But he's sure to be present, abroad or at home,
When children are happy and playing alone.
He lies in the laurels, he runs on the grass,
He sings when you tinkle the musical glass;
Whene'er you are happy and cannot tell why,
The Friend of the Children is sure to be by!
He loves to be little, he hates to be big,
'T is he that inhabits the caves that you dig;
'T is he when you play with your soldiers of tin
That sides with the Frenchmen and never can win.
'T is he, when at night you go off to your bed,
Bids you go to sleep and not trouble your head;
For wherever they're lying, in cupboard or shelf,
'T is he will take care of your playthings himself!