No Fungus Among Us

Difficulty: Hard ( Very Hard if done incorrectly )

Strategy
This achievement can be extremely difficult to obtain if done incorrectly, but very easy in I, Zombie levels.

Note: Grave Busters don't count as mushrooms, so you can use those.

Note: Doing an I, Zombie level without mushrooms such as the first one also counts for the easiest way to get this achievement, even on Game of the Year PC.

Note: Doing the first I, Zombie level on iPhone/iPod version of Plants vs. Zombies doesn't work, you won't get the achievement.

Note: Completing a Fog level without using mushrooms does not unlock this Achievement.

Note: Doing the Mini-game Whack a Zombie won't earn you this Achievement, even if you choose not to use Ice-shroom in the Mini-game.

Trivia

 * The achievement's name is based off and is a parody of the term "a fungus among us".
 * This is the reverse of the Achievement Good Morning.