Chronicles Of Riddick: Escape From Butcher Bay Easter Egg - The Butcher Boys

On your way in a Riotguard to Tower 19, you should come across a Briefing room. Shoot the guards inside, then when the coast is clear exit the Riotguard so you can enter the Briefing room. Look to the right to see a black and white photo credit of all the game developers- "The Butcher Boys"!