Imperial Bot is a robot that destroys something leaving an empty space. It does nothing on an empty space. Destroying a Bear or Ninja Bear will turn it into a Tombstone. It can not destroy a Chest. It will make you lose points for destroying an Item that earned you points. For example: if you destroy Grass you lose 5 points because Grass gives you 5 points. More information here. Like a Crystal, the Imperial Bot will apear about 2.5% of the time.