What makes a good parody song in general is an interesting question. I’ve penned good and bad ones in my time and to my mind, the original song needs to be well known with familiar lyrics, and the parody will use some of those original lyrics, but with some adjustment to alter their meaning to comic effect. Obviously some new lyrics are needed, but they shouldn’t stray too far from the original. More so than with non-comic songs, the rhyming pattern should be fairly elaborate (eg with internal rhymes) and strictly adhered to, ideally with some corny or excruciatingly bad rhymes in places, and the scansion should be precise throughout to enable occasional surprise comic words to be inserted where the scansion deliberately falters. Ideally there should be a joke or good play on words in each verse, with a good joke and or twist to the story at the end.

Few parodies tick all these boxes, but that’s often because they are not parodies of a particular song, but rather a comic critique that happens to use a familiar tune. Try this:

I was twenty one years when I lit this barbecue
I’m twenty two now and it’s still not cooked through
It’d be quicker to have stew
And the meat that was lean burns to brown
And it gives you chronic wind
And it rumbles in your glands

I threw my burger at a duck
And watched the cygnets run amok
And I never gave a f...urther thought
And the meat that was lean......etc.