If you have a group that enjoys learning idioms, here is a fun, one-page sheet of fish idioms that they can match up, along with some original artwork. Great for pair work discussion as they try to figure them out. Also leads to good discussions when you take it up, as similar sayings often exist in their first languages. This is a good 30-minute end-of-class exercise or to go with something else involving fish, the sea, summer, etc. 15-20 minutes of them working on it, 10 to 15 minutes of discussion as you take it up. (Answer key is on the second page). All for 99 cents!