The Shrimp by Ogden Nash

There once was
still is
a thing-a-ma-jig
who saw a companion across the brig

It hopped flopped and stopped of sorts
for in a puddle of goo was his gallant horse

on he rode or so he thought
like Don Quixote a ferrari bought
to ferry him across to the other side
of vainglorious self-worth and pride

but alas after much ado
it turns out the puddle was but poo
and so he slithered a way
a thing-a-ma-jig tomorrow
a thing-a-ma-jig today