The Chronicles of Riddick: Assault on Dark Athena

After the main credits you are deloused. Turn around and flush your toilet five times. When you leave your cell, find and enter Waman and Girish's cell. Flush their toilet five times. You will also have to activate Waman's Side-Mission [Kill Molina] or you can activate Shabby's Side-Mission [Kill Molina or both]. Talk to Mattsson in the Courtyard then go to his cell. When you enter Mattsson's cell you are ambushed by two other prisoners. Kill them and then flush Mattsson's toilet five times before leaving the cell. After the first the confrontation with Rust, Molina's cell door will open. Kill Molina then flush his toilet five times. After doing that, the Easter Egg will reveal itself within the Courtyard. There will be a picture on one of the walls. It will be of three of the developers with the words "Los Tres Amigos" [The Three Friends] at the bottom.

A bug exists which sometimes causes the in-flight sound effect of an Alpha Drone's rocket to persist after the missile has hit.

Edited from The Chronicles of Riddick: Escape from Butcher Bay (2004)