Well, obviously, there's an advantage in making your language obscure--weeds out the ferriners. But if you want obscure and animals, you should check out
nautical terminology. They've left out some good ones, though. A very heavy hemp cable,which has been soaked in hot pine tar and then erected as a temporary mast is called a horse. A boom traveler, an iron bar on which the sheet (which means, of course, a rope to the weather--windward--corner of the sail) was also traditionally called a horse. But when actually talking about animals, it wouldn't do to be too specific. So, the seaman detailed to take care of the chickens was called "Jemmy Ducks." Rats, which late in the voyage would often be hunted through the hold to be eaten, would be referred to as "millers."
The dog watches were two hours, rather than four, In one of the Aubrey-Maturin novels of Patrick O'Brian, there's pretty good scene when the Captain, Jack Aubrey, is dining in the gun room (where the other officers dine, but which does not house either the gunner, nor any guns), and the physician, Stephen Maturin is there, too, of course, in his capacity as ship's surgeon. Someone asks the origin of the term dog watch, and everyone is looking around puzzled, because no one knows. So Maturin says: "Because it's curtailed." Everyone looks at him blankly, and he's muttering under his breath about a wretched clench--until they finally figure out the joke. Then their hilarity knows no bounds, and Maturin is made that much more miserable.
So splice the messenger, and then we'll fish the cat.