User blog comment:Uselessguy/Guess Plants or Zombies in the whole series/@comment-25154254-20141024025613/@comment-24828059-20141024104724

Sheep. They turn back to plants after Wizards are killed.

Constructor Imps. They show that some worlds are not finished yet.

Digger Zombie and Prospector Zombie. After they get to the back of the lawn, they start going right.