Native-like proficiency in English requires learning idioms but they are difficult to master. Beginning with idioms having pictorial quality and universally known animals can greatly help initial learners of EFL for testing this hypothesis, learners from the first semester of five different BS programs at Kohat University of Science and Technology, were taught different idioms, in a one-month English language teaching program. They were evaluated at the end of the course at short notice. Eleven categories of idioms were formed and 20 idioms belonging to each category were set in the test. The learners scores on idioms involving common and well-known animals were higher as compared to the scores on another type of idioms. It was found that such idioms are learned, retained and recalled effectively because they rely on sound mental images and are easy to remember because of their tangibility, picturesqueness, imagery, and universally known common behavior.