Herman the Worm

I was sittin' on my fencepost
playin' with my yo-yo, do-whap, do-whap
And along came Herman the Worm
And he was this big
And I said "Herman, what happened?"
And he said "I swallowed a bug".

Start from the first verse again. .

Herman continues to get bigger and bigger as he eats larger animals each time.

The end:
I was sittin' on my fencepost
Chewing my bubblegum
When along came Herman the Worm
And he was this big (goes back to being small again)
And I said "Herman, what happened?"
And he said "I burped".