This is unlocked by letting the big guy catch you. He wears a striped red and black top. I unlocked this in the Ghetto level. It really is as simple as that. I think he may appear sooner in the game, but this is how I unlocked the achievement.
Thanks to DarqStalker for the following.
He does appear sooner in the game. About half way through the Outskirts level. You first see him in a building but he goes down some stairs that you can't access. After you pull a switch, he comes out and runs towards you if you don't get out in time. Just let him catch you.