Zack is an old friend of Pat's. He appeared in the episode The Real Book Club.


Zack was good friends with Pat back when they worked together, until he transferred to another branch. Back when Pat knew him, he was married to a woman named Kristy. Pat had met up with him again, a few years in the future and at this time, Zack had come out as a homosexual and gotten a divorce with Kristy. When he and Pat had a conversation about the events, there was an error in communication that led Zack to believe that he was also a homosexual. He invited Kenny and Pat both to play a game of gay dodgeball with them. When he realized that Pat wasn't actually gay, he shunned him out of their group of friends.