That was less than funny in my mother's day: it was sometimes rendered, with conscious antisemitism, as "You're mean Mr Sheen". And during a family singaround, when everyone was chorusing "adieu, my friends, adieu ", loudly staged whispered "aye, some of my best friends are Jews"... but that's not even a mondegreen, since he knew it.

My brother heard "Agnus Dei" as "aren't you staying"- you have to say it in Church Latin.

Leon Rosselson had an odd one. His version of "Le Déserteur" by Boris Vian starts "Messieurs qu'on dit les grands" rather than "Monsieur le Président". His French accent is even worse than mine.