More on Yarmouth Capons from Infoplease:

• Yarmouth Capons - Yarmouth Capons Red herrings. Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894 ...
• Capon - Capon Called a fish out of the coop by those friars who wished to evade the Friday fast by eating ...
• Dictionary of Phrase and Fable: Y - Definitions, origins, and illustrative excerpts for words, phases, and literary allusions starting with "Y"