Weepiper: Version of Cats on the Rooftops that I know (from the tradition) is a parody of John Peel

D'ye ken John Peel with his coat so grey
he's a very funny fellow, some folks say
'cos he doesn't do it in the normal way
but with his hounds and his horses in the morning

Cats on the rooftops, cats on the tiles
cats with syphilis, cats with piles
cats with their arseholes wreathed in smiles
as they revel in the joys of fornication

After than extemporise whatever filthy verses you like, usually with the last line
As he(she/they) revels in the joys of fornication