Back in the days when Stephen Pinker wrote books about language, he had a nice section about Latin and Greek plurals in English. Alumnus becomes alumni, cactus becomes cacti, and so on.
But it doesn’t always work. Sometimes we gave up pretending English is Latin (circus, museum). Sometimes it was never a Latin word to begin with (octopus).
or..Elvis. Pinker dug up this newspaper story:
“In Las Vegas, The Flying Elvi sued The Flying Elvises for trademark theft. Both organizations leap from airplanes in Elvis Presley (late period) costumes and dance and pretend to sing upon landing.”
They did indeed. The Flying Elvi lost on grammar but won in court, and their website testily asserts that they are “are the only officially licensed skydive team by Elvis Presley Enterprises®”
As for The Flying Elvises, I found some reminscences on a skydiving forum
I know Paul and his E team [yet another group of skydiving Elvises]. My buddy George and I groundcrewed a couple of his demos here in Vegas after we had quit being Elvis. Paul puts on quite a show with all the pyro , I was impressed.
Im guessing we did at least 75 or 80 demos coast to coast after the movie. I would have to look in my logbook , which I aint gonna do.
It was a ball until we got sued and that really sucked. Cost us 80 grand.