In Geoffrey Chaucer's Canterbury Tales, this human-faced cow is perpetually starved to skin and bone due to the scarcity of obedient and faithful wives. The Bicorne or Bycorne, a counterpart to the Chichevache which fed on obedient and kind husbands, was reputedly fat and plump because of the plentiful supply of such men.
Chaucer may have borrowed the French word chichifache ("thin face") to coin chichevache ("thin or meagre cow"). D. Laing Purves notes that "The origin of the fable was French; but Lydgate has a ballad on the subject. 'Chichevache' literally means 'niggardly' or 'greedy cow.'
Here is the paragraph where the word appears, in the "Clerk's Tale":