Text: Weird Al Yankovic. Amoeba.

The Amoeba is so small you need
A microscope to see one
It hurts the eyes, but I'll concede,
I'd rather see then be one
They never sing or laugh or talk
Or eat fondeaux or ciche
And if you take one for a walk
You need a tiny leash

I know the thing must have a brain
Although I couldn't tell you where
It sure must be an awful pain
To be so unicellular