So, randomly, I decided to look up the plural of conundrum today, and, as this illuminating discussion points out, "conundrum" isn't definitively Latin in origin. I particularly like the correction of the snob who insists that 'octopuses' is wrong:
I hope that Philip Moreland says octopodes not octopi, given that octopus is 3rd declension Greek not 2nd declension Latin. Actually I am sure he does, but for anyone to whom this is news, the word octopodes has four syllables.
In St Octopus's garden in the shade
He'd meditate just by the gate
While Gregorian Chant in the background softly played.
"St Octopus, would you tell us
What the plural of your name might really be?"
St Octopus just looked at us
"Children, that's not important at all to me.
I find when studying Theology
The greatest revelation is the Trinity."
"St Octopus, why not tell us,
it's just something that we find quite interesting."
He shook his head, and smiled and said,
"God's the only plurality that's worth knowing."