Not Baaad is an achievement in Plants vs. Zombies 2. It is achieved by completing a level with Wizard Zombies, without having them transform any of the player's plants into sheep. It is worth 10 points on Game Center for iOS devices and 1,000 XP on Google Play Games for Android devices.
Its name is a portmanteau of the generic sheep sound, usually represented as "Baaaa!", and the phrase "Not Bad."
It can be very difficult to get this achievement in the normal levels and the Endless Zone of Dark Ages except for 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. 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. You could also use Ghost Peppers because it can't be turned into a sheep. However, do not place plants on the Wizard Zombie's tile, or else it will transform the plant into a sheep. Grapeshot can work well if multiple Wizard Zombies are in the same row, as the bouncing grapes might destroy more Wizards. Be careful for Jester Zombies, as they will deflect the grapes.
- It, A-noob-is, Mutiny, All in Jest, Fly Fishing Fail, Shovel Off, Breaking It Off and You're an All-Star? all have similar objectives which are not letting those zombies use their special ability.