Red herring
It has long been thought that the phrase came from kippers (a strong-smelling smoked fish) to train dogs to follow a scent, or to distract them from the correct route when hunting. However, most researchers today believe that the term was probably invented in 1807 by English polemicist William Cobbett. He may have have been talking about a time which he had used a kipper to distract dogs from chasing a hare, and that hunters never actually used kippers to train dogs. The phrase was later borrowed to give a formal name for the logical fallacy and literary device.