From Elizabeth Daingerfield Zwicky, a link to a Nova "The Secret Life of Scientists and Engineers" piece on Jean Berko Gleason (shown with an enormous wug), here. Very charming."Wug", in the context, is a nonsense-word she coined for the "Wug Test", a cognitive test that examines children's ability to correctly form plurals (see her paper The Child's Learning of English Morphology for techie details). The wug is typically depicted as a bird-like creature. However, to me, "wug" is well fixed in my vocabulary (unused, alongside "kisser", "cakehole", "gob", etc) as a slang term for mouth, so it was as if the phrase read "shown with an enormous gob". It seemed so unlikely that Professor Zwicky would write something with such potential for misinterpretation that I looked it up, and found there to be vanishly few examples of its use in the meaning I'd acquired. However, I tracked down where I most likely picked it up: from a book I first read at 11 or so.
In the latrine he bobbed his head around trying to find a clear space on one of the mirrors. All of them had been heavily stenciled in large letters with such inspiring messages as KEEP YOUR WUG SHUT-THE CHINGERS ARE LISTENING and IF YOU TALK THIS MAN MAY DIE.There are a handful of Google hits, in forum posts, for variants on "keeping one's wug shut" = not blabbing. I wonder if the writers all similarly picked it up from Harrison's novel?
"We crashed!" Bill gasped. "Good as dead…" "Shut your wug. That was just the film what broke, Since there's no brass on this run they won't bother fixing it."
Bill, now that he had recovered from his first shock, was being a little crafty, remembering all the trouble he had gotten into by opening his big wug.
- Bill, the Galactic Hero, Harry Harrison, 1965
But returning to the Jean Berko Gleason usage, I also wondered if "wug" isn't merely a nonsense-word in that context. Looking at Google Books - see the 1845 Oneóta: or Characteristics of the red race of America from original notes and manuscripts (page 103) and other works by Henry Rowe Schoolcraft - it appears that in the Chippewa language, "wug" is the suffix used to form plurals of adjective-noun combinations involving animate creatures. Its use by a linguist in a test about plural formation for a little creature seems
Edit made in the light of Professor Zwicky's comment to the effect that the vast search space - a small syllable across all languages - makes such a coincidence, and even semantic coincidence, unremarkable. Point taken, and being well aware of false cognates, I should have been more cautious about it! However, it did lead up a nice linguistic byway.