Some Mad "nursery rhymes" that have stuck with me all these years:

When Onassis goes broke,
and the H-bomb's a joke,
and bookies no longer take bets,
when bacon is kosher,
then Leo Durocher
will win seven straight from the Mets!
*
Twinkle, twinkle, man with star,
officer, don't tag my car!
Though it's double-parked and waits,
can't you see my M.D. plates?!
*
If wishes were horses, we'd all ride for free.
If Huntley were Cronkite, we'd watch NBC!

(to the tune of "The Caissons go marching along")
In a test
for a class
that we know
that we can't pass
see the goof-offs go faking along!

Start to heave,
fake a chill,
anything so's you'll look ill,
as the goof-offs go faking along!

For it's hi hi hoo,
we'll all fake the Asian flu!
Call out your symptoms loud and strong (blah! ecch!)
We will feel enthused
when the teacher says excused
as the goof-offs go faking along!

Ya gotta be ancient to appreciate these :)