Zack is noted to be an delinquent vandal who toilet paper rolled Woodstone Mansion for the past few years with the tradition coming to the end in Halloween after he and his friends are blamed for burning down the gazebo, although unknown to the police Thor did that by accident which the other ghosts used the opportunity to pin the blame on Zach so he would stop coming by and vandalizing the house. It worked, although Zach did give Sam and Jay an warning sign when picked up by his mom.
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