I think Wesley's mum's line is actually better than the original.
This isn't exactly a mondegreen, but close. Recently on the Mudcat I was looking for a song called "The bears have got my Daddy", which I'd found on a tape of tunes from a sort of musical box.
Couldn't be found anywhere. Then someone who runs a site about musical boxes solved the puzzle. "The Boers have got my Daddy." A great little song.