"One Dangerous Zombie" is a feature in the Resident Evil remake which sees a zombified and essentially invulnerable Forest Speyer wandering the mansion. It is unlocked in the 2002 GameCube version by completing Jill Valentine and Chris Redfield's scenarios twice each (playing "Once Again..." for both characters). In the HD remaster, it is unlocked by completing Chris and Jill's scenarios once each on Normal or Hard difficulty. Rather than being a separate mode, this feature becomes a permanent part of each "Once Again..." playthrough of the game and cannot be turned off.