He is first mentioned indirectly in Nana Gallagher Had an Affair, where Fiona mentions to her siblings their father has three brothers.
During Daddyz Girl, Lip and Ian visited their grandmother Peggy Gallagher who listed Jerry among her other sons. Peggy also claims Jerry owes her five thousand dollars while asking Lip and Ian to tell him to pay it back or she'll have her ex-husband visit him and gouge out his eye. The brothers visited Jerry who was unaware of who the boys were until he was informed both were his brother Frank's sons, making them his nephews which shocked him. Realizing they want something; Jerry then ran back inside his house. Lip and Ian were shocked their father had a twin and tried to connect with him since he was family. However, Jerry threatened to shoot his nephews with his shot gun if they didn't leave and they quickly complied.
In Parenthood, Peggy mentions Jerry again with her other sons Clayton and Wyatt voicing how proud she is they stayed out of jail. A dying Peggy would send the remainder of her money to Jerry and the others.
- A Jailbird, Invalid, Martyr, Cutter, Retard, And Parasitic Twin (mentioned only)
- It is unknown which twin is older Frank or Jerry.
- It appeared he wasn't on good terms with his brother Frank, since he wanted nothing to do with him in his nephews visit.
- Frank does not seem to like Jerry either as he mentioned that he was one of the favorites of his parents.
- It is unknown how Jerry reacted to Frank dying.
- It was shown that he wasn't on good terms with his mother, since he owed Peggy money and most likely knew she was involved in his nephews visit.
- Peggy also seemed irritated with Jerry for not paying her back and wanted to hurt him.
- Before she died, she sent Jerry money.
- It is unknown if he is on good terms with his other brothers Clayton and Wyatt.
- It is also unknown what terms he is on with other relatives: his father, his grandmother, his late aunt, his Uncle George, his nephew Jacob, cousin Patrick, and Patrick's kids.
- Ian took an immediate dislike to Jerry for his actions and didn't want him to be his potential father.
- He may work at a factory since he was wearing a uniform with his name tag.
- Unlike Clayton, it hasn’t been revealed whether Jerry has children or not.