Two by Spike Milligan:

Lady Barnaby takes her ease,
knitting overcoats for fleas.
By her kindness fleas are smitten,
that's why she's very rarely bitten. .....or

Lord Finchely tried to mend the electric light bulb himself.
Killed him dead,
served him right.
'Tis the purpose of the businessman
to give employment to the artisan.

B.