the only time I had frogs' legs was after we'd all ordered random things of the menu, and the chap who'd actually ordered them took one horrified look stating "I can't eat that" so I swapped. Amusingly the one (just about) French speaker then said "ah, I remember what grenouille are now"
They were nice enough (chicken basically) but not really worth the trouble.
But there was also the "Agneaux" incident which I duly ordered. Waiter pointed out (in English) "you do know it's brains don't you?" As it happens my schoolboy French covered "lamb" but not "brains" - but I obviously couldn't lose face in front of Johnny Foreigner so said "yes of course, that's fine". Three whole lambs' brains arrived presently - nice enough but not something I'd order again on purpose. Still, British honour was upheld and that's the main thing