Core, The Easter Egg - Flying Fish in the Core

In the film sequence where the birds go nuts in Trafalgar Square, there is one scene where a flock of birds crash through the plate glass windows of a building. The scene starts with a family video taping their vacation and as the birds go crazy, the family winds up fleeing to this building with the large windows in the front. When the birds start striking the windows, slow the scene down and you will clearly see that one of the birds is actually a trout.