Not Baaad

Difficulty: Hard-very hard

Not Baaad is an achievement in Plants vs. Zombies 2. It is achieved by completing a level infested with Wizard Zombies, which cannot transform plants into sheep. It is worth 1,000 XP on Google Play Games for Android devices, and ten points on Game Center for iOS devices.

Strategies
It is very difficult to get this achievement in the normal levels of Dark Ages except Dark Ages - Night 11. It is recommended to get this achievement on the first level of Arthur's Challenge or Dark Ages - Night 11 because only a few Wizard Zombies will appear. Then, use instant-kill plants like Cherry Bomb to dispose of them quickly so that they do not transform any of your plants. You can also use Iceberg Lettuces (also when boosted) to freeze Wizard Zombies and then the Cherry Bomb (along with its Imitater version) as a one-use combo to get this achievement on the first level of Arthur's Challenge. Imitating instant-kill plants can be useful to destroy the Wizard Zombies.

Trivia

 * The name of this achievement is a pun on a sheep's sound, that is usually referenced to as "Baaaa!".
 * This, A-noob-is, Fly Fishing Fail, Mutiny, and All in Jest have similar objectives.