Glenn is a castaway living on a deserted island for almost five years that is unaware of the virus that Carol and the group meet up with after losing course on their trip to Mexico.
When the group loses course on their trip to Mexico in "M.U.B.A.R.", they discover an island and travel there by dingy, when Pamela knocks out Phil, separates them from their yacht and abandons them, forcing them to head to the island, where they are unknowingly spotted by Glenn.
In "Stocko Syndome", they try to make the best of their little supplies, before encountering Glenn on the island. Glenn introduces them to his living situation, where they find his sex doll and discover that he is completely unaware that the virus happened. Later on, they try to tell him, but with his hopes and intentions to see his family, including his oldest son, Tommy, his daughter, Penny, who was thought to have a short life expectancy, and his youngest son, Dougie, who's mother passed away when she was giving birth. After his sad story, the group chooses to not tell him.
As Carol worries about never seeing Phil again, Glenn comes to her and reveals that he has a signal fire, but is saving it for a boat or plane. She reveals to him that the entire world was wiped out. He confesses later that night to Carol that he was foolish, but she insists that he was hopeful. They decide to light the signal fire, which covers a big portion of the island. Pamela also feels guilt about what she did to Phil and the others, and spots the signal fire in the distance. Phil and Carol reunite the next day as the group contemplates on what to do with Pamela. The majority of them agree to leave her on the island, as she pleads the group to take Jeremy with them. Glenn notes that she will have no hope of being rescued and decide to bring Pamela with them anyway, but on the condition that she rides connected to the boat in the dingy.
In "Skeleton Crew", Carol finishes shaving Glenn's face and discovers that they also left Jasper back on the island. Meanwhile, Pamela is welcomed back to the boat, after falling out of the yacht and slowing down their arrival to Mexico. She tries her best to make amends by offering various tasks. Later that night, Glenn brings her dinner and their conversation eventually leads to sex. Carol and Gail confront Pamela about this, but she plays it off, as Glenn tries to persuade Pamela to come join the group. When Glenn tries to tell the group about his relationship with Pamela, Jasper spots Zihuatanejo, entirely covered in body bags. Glenn also has a sudden change of attitude, after noticing a flyer for a missing child.
As Glenn breaks up with Pamela, Carol shows Phil their new residence, which is a hospital, nearby a motel. She then notices Pamela crying outside in a nearby courtyard. At dinner that night, Carol invites Pamela to dinner and forgives her for what she did to the group. However, Glenn objects to this and Pamela demands to know why Glenn is treating her poorly.
Glenn confesses that he loves her but plans to leave the next day to return to the United States in search of his kids, despite the radiation. As Glenn says his goodbyes the next day to the group, Pamela decides to go with Glenn on his trip. She thanks the group for forgiving her and drives off with him and Jeremy.
He is portrayed by Chris Elliott.