This is an "almost limerick" for Mrs. Enos, proprietress of the only General Store in Limerick, Maine.  Limerick, that place, was a textile-making town at one time.  Along came the thought of wool and the sheep from which it comes.  The flu season, being upon us, did the rest. 

A dull-witted sheep ambled through.
That's something a smart sheep won't do.
His hair's now a blanket.
Did anyone thank it
or say to him, "don't catch the flu?"