Whether you want to proudly keep this achievement for a later unlock to make it look good on your game-history, the earliest opportunity is right after the very first dining room scene with Barry when you play as Jill Valentine. With Chris Redfield there won't be a scene but you start in the same room.
Check the door to your right (next to the fireplace) and enter it. In the hallway make your way to the left and trigger a cutscene. Now all you gotta do it is let the zombie have fun eating you until you're dead.