More on Fat as a Porpoise from Infoplease:

• Fat as a Porpoise - Fat as a Porpoise The skin of the porpoise is nearly an inch thick, and under it is a layer of fat ...
• porpoise - porpoise porpoise, small whale of the family Phocaenidae, allied to the dolphin. Porpoises, like ...
• Dictionary of Phrase and Fable: F - Definitions, origins, and illustrative excerpts for words, phases, and literary allusions starting with "F"