In Two Shakes of a Lamb's Tail

Etymology:

• In 19th century, there was a saying, ‘two shakes’ suggesting something to occur quickly. But many wondered about two shakes of what? Two shakes did not clearly referred to a particular thing, eventually it was thought by an imaginative person to refer to “two shakes of a lamb’s tail” with the idea that lamb’s tail shakes very quickly. You can observe this in a lamb. Today the phrase “two shakes of a lamb’s tail” is used to suggest any thing that happens too quickly.