The short answer is, this is a wug:
The wug was invented by linguist Jean Berko Gleason as part of a language acquisition experiment. Gleason wanted to find out when children learned to make English plurals. So she drew small creatures with made-up names, like the wug, and set up a task where children were prompted to say plural forms of the words. The prompt looked like this:
The English plural of wug would be pronounced with a [z] sound on the end, [wʌgz]. If children produce this form, it means they’ve learned a general rule about creating English plurals, rather than simply memorizing the singular and plural of each noun. Gleason found that most preschoolers know how to make this plural (76%), and that almost all children aquire it by around age six (97% of first-graders). She published these results in an 1958 article “The Child’s Learning of English Morphology”.
Wugs are just so cute, they became the unoffical mascot of linguistics. You’ll find them on mugs and t-shirts, and I embroidered one in the center of my animal-themed English vowel chart (for the IPA vowel [ʌ]).
Yeah sure I started grad school and resubmitted a journal article but my proudest accomplishment of 2017 is this embroidered English vowel chart pic.twitter.com/d78m8KADHm— May Helena Plumb (@mayhplumb) December 6, 2017
Want to learn more? Wugs are all over the place.