are sheep for sheep and fish or fishes for fish. Sheeps is only a form of a verb. Sheeps means grazes. Yes, the plural of "whim" is boring old "whims." However,there is "cacti" and "cactuses." Even more fun is that there is "octopi," "octopuses," and "octopodes." More plurals fun: rhinoceroses, rhinoceri, rhinocerotes.

Yes, I'm afraid I also fond FGZstar's poster both meaningless and mildly offensive.
[Plural] I still occasionally come across people who insist "data" can only be a plural. Funny that they don't make the same fuss about "agenda".

[INJ/SM] I presume it was intended as the opposite of the magnificent "Keep Calm and Carry On" posters of the Second World War.

(ISP) I think "data" can be both but I agree that to insist that it is always plural is pretentious and a bit annoying, a bit like government propagandums.
(Phil) Don't quite remember 'em, but if you say so. :-)

[Phil] Thanks. I'm not overly conversant with WWII UK memes unfortunately. In fact, Mr. Chad (known elsewhere as Kilroy) is the sum total of my knowledge of the matter. Or was, since I now know something else thanks to you and FGZStar.