“My Shadow” by Robert Louis Stevenson
One of my personal favorites:
I have a little shadow that goes in and out with me,
And what can be the use of him is more than I can see.
He is very, very like me from the heels up to the head;
And I see him jump before me, when I jump into my bed
The funniest thing about him is the way he likes to grow –
Not at all like proper children, which is always very slow;
For he sometimes shoots up taller like an Indian-rubber ball,
And he sometimes gets so little that there’s none of him at all.
~Robert Louis Stevenson~