Doctor Foster travels to Gloucester in the rain and steps straight into a puddle up to his middle. Four lines, one pratfall, and enough comic timing that children ask for it again.
From Mother Goose / Nursery Rhymes (traditional). See the whole collection.
Doctor Foster went to Glo'ster,
In a shower of rain;
He stepped in a puddle, up to his middle,
And never went there again.
Public domain. Text from The Real Mother Goose (Blanche Fisher Wright, 1916), via Project Gutenberg. View the source edition