That's the one. Thanks!

I didn't mean "comic" in the sense of dismissive or belittling, if that's what you thought, but rather in the sense of pawkieness:

"He seen a smoke way up de ribber, whar de Linkum gunboats lay;
He took his hat, and lef' berry sudden, and I spec' he's run away!"

It's slyly contemptuous humor about someone for whom the singer has, quite rightly, no kindly feelings of any sort.