The player can earn this achievement by typing "mustache" or "moustache" while the game is being played. The player can activate this code at any time in the game. There are three types of mustaches as seen below.
Ask Me About Mustache Mode achievement
If the player does this in the Steam version, the player will unlock the achievement Ask Me About Mustache Mode. In the Game of the Year edition, this was simplified to Mustache Mode. These achievements are regarded as the easiest achievement in the game, since they require no skill.
Gallery of mustached zombies
- The mustache resembles Ladder Zombie's mustache, except these types are black.