Theme 2-1 is the 22nd level of Poached Eggs and the first level of Theme 2.
Fire the Red bird so that it kills the Corporal Pig and the Large Pig after it and then hits the left support on the structure holding the small pigs and kills the many small pigs on top of it. This shot is tricky and difficult, as it can take a long time to get this shot. Then use the first yellow bird to finish off the leftmost pig. The two unused birds award the player 20,000 extra points.